Treatment of post-bariatric hypoglycemia with exendin (9-39)

ABSTRACT

Compositions and methods for treating hyperinsulinemic hypoglycemia, such as hyperinsulinemic hypoglycemia after bariatric surgery, are provided. In some embodiments, an effective amount of the glucagon-like peptide-1 receptor antagonist exendin(9-39) is subcutaneously administered twice per day.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 15/576,647, filed Nov. 22, 2017, which is the National Stage of International Application No. PCT/US2016/033837, filed May 23, 2016, which claims priority to U.S. Provisional Application No. 62/165,743, filed May 22, 2015, U.S. Provisional Application No. 62/254,175, filed Nov. 11, 2015, and U.S. Provisional Application No. 62/329,850, filed Apr. 29, 2016, the contents of each of which are incorporated by reference herein.

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

This invention was made with Government support under contract TR001085 awarded by the National Institutes of Health. The government has certain rights in the invention.

FIELD OF THE INVENTION

The present invention provides methods and compositions for the treatment of hypoglycemia, particularly post-bariatric hyperinsulinemia, and more generally hyperinsulinemic hypoglycemia of any origin, and the prevention of associated acute symptoms and chronic outcomes in which a glucagon-like peptide-1 receptor antagonist (GLP1A), exendin(9-39), is subcutaneously administered in a therapeutically effective dose. The invention therefore relates to the fields of biology, chemistry, medicinal chemistry, medicine, molecular biology, and pharmacology.

BACKGROUND OF THE INVENTION

Roux-en-Y gastric bypass (RYGB), widely performed for medically complicated obesity, cures type 2 diabetes in 85% of cases. The physiologic mechanisms mediating diabetes resolution is controversial, but the reduction in glucose excursions prior to weight loss has led to postulates that the incretin hormone, glucagon-like peptide-1 (GLP-1), may play an important role. GLP-1 stimulates the secretion of insulin by pancreatic beta cells and is responsible for the “incretin” effect: incretin hormones enhance the glucose-dependent secretion of insulin, such that pancreatic beta cells will secrete more insulin after an oral glucose load than after an isoglycemic IV glucose load Enhanced secretion of GLP-1 after RYGB, and a resultant elevation in insulin secretion, may play a primary role in the resolution of diabetes after RYGB. Indeed GLP-1 analogs have been developed to treat diabetes.

However, as the use of bariatric surgical procedures continues to increase worldwide, a severe complication—hyperinsulinemic hypoglycemia—is increasingly reported. Present in 1-6% of RYGB patients, this disorder leads to severe symptomatic hypoglycemia that plagues patients often multiple times daily, with glucose concentrations low enough (20-40 mg/dL) to cause seizures, altered mental status, loss of consciousness, cognitive dysfunction, disability, and death. Quality of life is severely diminished, and many patients cannot care for themselves or others, work, drive, or be left alone. There is no effective treatment and severe cases have been managed with near-total to total pancreatectomy, which results in insulin-dependent diabetes and is associated with a 6% surgical mortality risk.

Given the severity of this chronic disorder with unmet clinical need, an effective therapeutic treatment is urgently needed. It would thus be useful to provide a method for the treatment of hyperinsulinemic hypoglycemia post bariatric surgery and prevention of its acute symptoms and chronic outcomes, and a pharmaceutical composition for such therapeutic.

SUMMARY OF THE INVENTION

The present invention relates to pharmaceutical compositions and methods involving twice-per-day subcutaneous delivery of exendin(9-39) in doses therapeutically effective for treating or preventing hyperinsulinemic hypoglycemia in a patient who has previously had bariatric surgery, such as Roux-en-Y gastric bypass surgery. The twice-per-day administration is generally a first administration in the morning and a second administration in the evening. In a particular embodiment the twice-per-day subcutaneous delivery involves administering a composition comprising a therapeutically effective amount of exendin(9-39), wherein the therapeutically effective amount is in the range of 10 mg-30 mg exendin(9-39). In some embodiments the therapeutically effective amount of exendin(9-39) administered twice-per-day is in the range of 10-20 mg (e.g., 10 mg, 15 mg, or 20 mg), in the range of 10 mg-15 mg (e.g., 10 mg or 15 mg), or in the range of 15 mg-30 mg (e.g., 15 mg, 20 mg, 25 mg, or 30 mg). The exendin(9-39)-containing composition may be a solution or suspension that comprises exendin(9-39) at a concentration in the range of 4-20 mg/ml. In some embodiments the concentration is in the range of 10-20 mg/ml. In some embodiments the concentration is in the range of 8-16 mg/ml. In some embodiments the concentration is in the range of 13-16 mg/ml.

In some approaches the composition, or injectate, administered in the morning administration and the composition, or injectate, administered in the evening administration are the same, i.e., they contain the same amount (dose) of exendin(9-39) at the same concentration. In another approach subcutaneous administration twice-per-day comprises administering a morning injectate and an evening injectate, where the amount and/or concentration of exendin(9-39) in the evening injectate is greater than the amount of exendin(9-39) in the morning injectate. In one approach the amount of exendin(9-39) in the evening injectate is greater than the amount of exendin(9-39) in the morning injectate. In one approach the concentration of exendin(9-39) in the evening injectate is higher than the concentration of exendin(9-39) in the morning injectate.

In some cases, the amount of exendin(9-39) in the evening injectate is 5 mg-10 mg greater than the amount in the morning injectate. In some such cases the amount of exendin(9-39) in the morning injectate is 10 mg and the amount in the evening injectate is 15 mg. In some such cases the amount of exendin(9-39) in the morning injectate is 10 mg and the amount in the evening injectate is 20 mg. In some such cases the amount of exendin(9-39) in the morning injectate is 15 mg and the amount in the evening injectate is 20 mg. In some such cases the amount of exendin(9-39) in the morning injectate is 15 mg and the amount in the evening injectate is 25 mg. In some such cases the amount of exendin(9-39) in the morning injectate is 20 mg and the amount in the evening injectate is 25 mg. In some such cases the amount of exendin(9-39) in the morning injectate is 20 mg and the amount in the evening injectate is 30 mg.

In some cases, the concentration of exendin(9-39) in the morning injectate is not the same as the concentration of exendin(9-39) in the evening injectate. For example, in one approach the concentration of exendin(9-39) in morning injectate is 15 mg/ml and the concentration of exendin(9-39) in the evening injectate is 20 mg/ml.

In some cases the exendin(9-39) amount and concentration of the morning and evening injectates are selected such that the exendin(9-39) Tmax after the evening administration is longer than the Tmax after the morning administration.

In some cases the amount and concentration of the morning and evening injectates are selected such that the administration results in an exendin(9-39) Cmax of at least 100 ng/ml (e.g., as measured by liquid chromatograph-mass spectrometry).

In some approaches administration comprises a first daily administration is in the morning and a second daily administration in the evening, where the second daily administration is at least 8 hours after the first daily administration. In some such cases the morning administration is administered before the morning meal (e.g., breakfast). In some such cases the morning administration is administered at least 1 hour before the morning meal, optionally 60 to 90 minutes before the morning meal. In some cases the morning administration is in the period from one hour before the morning meal to one hour after the morning meal. In some cases the second daily administration is administered 60 to 90 minutes before the evening meal. In some cases the second daily administration is administered after the evening meal and before bedtime (for example, within 2 hours of bedtime). In some cases, the evening administration is from 9 to 15 hours after the morning administration.

In some embodiments, a dose of exendin(9-39) is administered with regard to the timing of a meal. For example, in some embodiments, the dose of exendin(9-39) is administered with a meal, or before a particular meal, including, for example a certain time, e.g., 15 minutes to two hours, e.g. one hour, before a meal, or a certain time after a meal.

In some embodiments, a dose of exendin(9-39) is administered without regard to the timing of a meal.

In one embodiment of the invention, the patient self-administers (or is wearing a device programmed to administer) the exendin(9-39). In some embodiments, the first dose may be administered in the evening, such that it provides protection during breakfast the following day, with subsequent doses following the next morning and the next evening about twelve hours later.

In some embodiments, exendin(9-39) is formulated and administered in an injectable pen device or via a vial/syringe combination that may be pre-programmed or marked to deliver a fixed dosage amount (and optionally two different fixed dosage amounts corresponding to morning and evening administrations) ranging from 10-30 mg exendin(9-39).

The pharmaceutical compositions of the invention have use for treatment and prevention of hyperinsulinemic hypoglycemia and its associated symptoms and outcomes in patients with hyperinsulinemic hypoglycemia post bariatric surgery and post gastrointestinal surgery. In these and other embodiments, the invention provides for the prevention and treatment of associated acute and chronic symptoms and outcomes in susceptible patients. Treatment in accordance with the invention of patients in need of therapy will improve patient quality of life both in the short- and long-term, will reduce overall patient morbidity, and may prevent premature death and/or extend life-expectancy.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A and FIG. 1B. Average plasma glucose response (FIG. 1A) and average insulin response (FIG. 1B) to a 75 gram oral glucose tolerance test (OGTT) in subjects with hyperinsulinemic hypoglycemia during a randomized blinded cross-over study in which a primed continuous intravenous (IV) infusion of exendin(9-39) (at 500 pmol/kg/min over 180 minutes) or placebo (normal saline) was administered, as described in Example 1. Solid line: placebo infusion; dashed line: exendin(9-39) infusion.

FIG. 2A, FIG. 2B and FIG. 2C. Average plasma GLP-1 response (FIG. 2A), average GIP response (FIG. 2B), and average glucagon response (FIG. 2C) to a 75 gram OGTT in subjects with hyperinsulinemic hypoglycemia receiving primed continuous IV infusion of exendin(9-39) of 500 pmol/kg/min over 180 minutes versus placebo (normal saline) infusion, as described in Example 1. Solid line: placebo infusion; dashed line: exendin(9-39) infusion.

FIG. 3. Individual and average symptomatic responses to a 75 gram OGTT in 8 patients with hyperinsulinemic hypoglycemia receiving a primed continuous IV infusion of exendin(9-39) versus placebo, as described in Example 1. Overall Symptom Score, Glucose Rise, and Glucose Fall Scores are presented. Continuous IV infusion of exendin(9-39) at 500 pmol/kg/min over 180 minutes substantially improved symptoms of hypoglycemia, as demonstrated by the reduced Overall Symptom and Glucose Fall scores.

FIG. 4A, FIG. 4B, FIG. 4C, and FIG. 4D. Plasma glucose responses to IV bolus doses of 7,500 pmol/kg of exendin(9-39) administered to a subject with hyperinsulinemic hypoglycemia at different time points relative to the timing of administration of glucola in an OGTT. Specifically, the exendin(9-39) IV bolus was administered at: T=0 minutes (FIG. 4A), T=20 minutes (FIG. 4B), or T=50 minutes (FIG. 4C). For FIGS. 4A-4C, glucose levels measured at specific timepoints as described in Example 2 are shown by a solid line. For FIGS. 4A-4D, the projected exendin(9-39) PK curve after administration of the IV bolus of 7,500 pmol/kg is shown by a dotted line. Dosing at 0 minutes (FIG. 4A) or 20 minutes (FIG. 4B) did not prevent hypoglycemia, whereas dosing at 50 minutes (FIG. 4C) did prevent hypoglycemia. The GLP-1 peak for the subject in FIG. 4C occurred at 60 minutes, suggesting that timing the administration of the IV bolus to the GLP-1 plasma peak was necessary to prevent hypoglycemia.

FIG. 5A and FIG. 5B. In FIG. 5A, average plasma exendin(9-39) concentrations for 8 human subjects administered a continuous exendin(9-39) IV infusion at a rate of 500 pmol/kg/min over 180 minutes are plotted (black line), wherein the projected exendin(9-39) pharmacokinetic response to a single IV bolus of 7,500 pmol/kg exendin(9-39) administered at T-30 (blue line) was extrapolated based on the known half-life of intravenously administered exendin(9-39). In FIG. 5B, a single IV bolus of 7,500 pmol/kg exendin(9-39) or a single subcutaneous injection of 7,500 pmol/kg exendin(9-39) was administered to a subject, wherein plasma exendin(9-39) concentrations were measured by liquid chromatography-mass spectrometry (LCMS), and wherein the Cmax that was observed in subcutaneous administration of exendin(9-39) was significantly lower than the Cmax observed in intravenous administration of exendin(9-39).

FIG. 6. Average plasma glucose levels during a 75 gram OGTT for subjects administered a subcutaneous dose of exendin(9-39) as compared to baseline. Four subjects received one subcutaneous injection of 35,700 pmol/kg, 75,000 pmol/kg, or 112,500 pmol/kg (approximately 10, 20, or 30 mg, respectively, based on an 80 kg patient) in a volume of 0.7 ml normal saline, and four subjects received two or more 0.7 ml injections of 35,700 pmol/kg, 75,000 pmol/kg, or 112,500 pmol/kg in order to maintain an injectate concentration of 15 mg/ml or less. The average plasma glucose nadir for all 8 subjects during subcutaneous injection of exendin(9-39) was 78 mg/dL vs. <50 mg/dL during a baseline oral glucose tolerance test, demonstrating that subcutaneous injection of a single dose about 10-30 mg exendin(9-39) was able to effectively reverse hyperinsulinemic hypoglycemia.

FIG. 7A and FIG. 7B. FIGS. 7A and 7B demonstrate plasma exendin(9-39) concentrations following subcutaneous injection of exendin(9-39). In FIG. 7A, three subjects received a single subcutaneous injection of approximately 10, 20, or 30 mg of exendin(9-39) in a volume of 0.7 ml (5 x, 10 x, or 15 x doses, respectively). In FIG. 7B, five subjects received doses of approximately 2, 10, 20, or 30 mg (lx, 5 x, 10, or 15 x, respectively), with each dose administered at a concentration of 15 mg/ml or less; higher doses were administered via more than one injection so as to maintain a relatively dilute concentration.

FIG. 8. Percent increase in plasma glucose nadir concentrations were calculated for the subcutaneously administered doses of exendin(9-39) relative to baseline. A correlation was observed between higher percent increases in plasma glucose nadir concentrations and increasing peak plasma exendin(9-39) concentrations (C_(max)).

FIG. 9. Study design for 3-day Multi-Ascending Dose Trial to assess the safety, tolerability, efficacy, and pharmacokinetic profile of BID exendin(9-39) administered subcutaneously over 3 days to patients with post-bariatric hyperinsulinemic hypoglycemia.

FIG. 10. Exendin(9-39) plasma concentrations on Day 3 after 5 doses as described in Example 4.

BRIEF DESCRIPTION OF THE TABLES

Table 1: Metabolic responses to a 75 gram oral glucose tolerance test (OGTT) during primed continuous IV infusion of exendin(9-39) in eight post-RYGB patients with hyperinsulinemic hypoglycemia (HH). Metabolic responses of eight BMI, age, and sex matched non-surgical controls are presented for comparison. AUC values were calculated by the trapezoidal rule utilizing the last value carried forward to account for prematurely discontinued OGTTs in cases of hypoglycemia, which occurred solely during placebo infusion.

Table 2: Mean plasma GLP-1, GIP and glucagon response to a 75 gram oral glucose tolerance test (OGTT) in eight patients with hyperinsulinemic hypoglycemia (HH) during a primed continuous IV infusion of exendin(9-39) of 500 pmol/kg/min over 180 minutes vs. during placebo (normal saline) infusion.

Table 3: Subject metabolic and symptomatic response to a single subcutaneous (SC) injection of 10-30 mg of exendin(9-39), denoted as SC Ex(9-39), continuous IV infusion of exendin(9-39 (IV Ex(9-39)), or placebo during a 75 gram OGTT. This table demonstrates that clinical efficacy during this SAD subcutaneous injection study was comparable to that achieved during continuous IV infusion of exendin(9-39), as measured by the plasma glucose nadir, AUC glucose, and the Symptom Fall Score.

Table 4: PK/PD response to increasing doses/increasing concentrations. As described in Example 3, subjects 2-5 each received a subcutaneous injection of exendin(9-39) in doses ranging from 37,500-112,500 pmol/kg (approximately 10-30 mg) each in a volume of 0.7 ml, resulting in dose concentrations of approximately 15-40 mg/ml. Shown here are subject PK/PD responses to each dose. Injectate concentrations of approximately 15 mg/ml resulted in the greatest pharmacodynamic response, as defined by nadir postprandial glucose and AUC glucose, and greatest pharmacokinetic response, as defined by Cmax and DN Cmax. Thus a relatively dilute dose may be preferred for BID dosing, and a more concentrated formulation may be preferred for less frequent dosing or a more sustained exposure. The 75,000 pmol/kg dose (17 mg) with a concentration of about 24 mg/ml resulted in a favorable sustained/slow release pharmacokinetic response, with a half-life of 9.14 hours, and a Cmax that was 70 or more ng/ml. Thus a relatively concentrated dose may be used advantageously for qD or BID dosing not tied to meals.

Table 5: PK/PD response to increasing dose with constant injectate concentration. As described in Example 3, four subjects received subcutaneous injections of 37,500-112,500 pmol/kg exendin(9-39) in equivalent concentrations (approximately 13-16 mg/ml), as this concentration was found to result in a favorable immediate release formulation of the invention. Results shown demonstrate an increasingly favorable PK response with increasing dose, as defined by Cmax and T_(1/2).

Table 6: PK/PD response in four subjects dosed with varying doses of subcutaneously administered BID exendin(9-39) in a 3-day clinical trial as described in Example 4.

DETAILED DESCRIPTION OF THE INVENTION 1. Introduction

Post-bariatric hyperinsulinemic hypoglycemia is a disorder that is characterized by low blood sugar and elevated insulin levels 1-3 hours after meals. The disorder manifests as neuroglycopenic symptoms (such as confusion, loss of focus, fatigue, ataxia, paralysis, seizures, or loss of consciousness), vasomotor symptoms (such as sweating and shakiness), and/or adrengeric symptoms (such as heart palpitations). Although the pathogenesis of post-bariatric hyperinsulinemic hypoglycemia is not entirely understood, several mechanisms have been proposed, including increased secretion of insulinotropic incretin gut hormones from the hindgut, expansion in β-cell mass, enhanced β-cell sensitivity, increased insulin sensitivity, decreased insulin clearance, reduced ability to mount a counterregulatory glucagon response, and absence of a prodiabetogenic/decretin foregut factor.

As described in Example 1, in patients having hyperinsulinemic hypoglycemia after gastric bypass surgery, blockade of the Glucagon-like Peptide-1 (GLP-1) receptor by administration by primed continuous intravenous (IV) infusion of exendin(9-39) effectively reversed hyperinsulinemic hypoglycemia and associated symptoms. In this trial patients received a total dose about 24-39 mg exendin(9-39), with the drug quantity varying with patient weight. (Also see Salehi et al., 2014, “Blockade of Glucagon-like Peptide 1 Receptor Corrects Postprandial Hypoglycemia After Gastric Bypass,” Gastroenterology 146:669-680.) However, because post-bariatric hyperinsulinemic hypoglycemia is a chronic, lifelong disorder, the administration of a continuous IV infusion of exendin(9-39) is not a practical treatment option.

Exendin(9-39) administered intravenously is characterized by a short plasma half-life of 33 minutes (see, Gardiner et al., JPET 316:852-859 (2006); see also, Edwards et al., Diabetes 48:86-93 (1999)). As described in Example 2, below, exendin(9-39) administered as a single IV bolus of 7,500 pmol/kg prevented hypoglycemia in patients only if the bolus was timed to closely coincide with peak GLP-1 plasma concentrations. The pharmacokinetic properties exhibited from the administration of a single intravenous dose of exendin(9-39) are such that a person of ordinary skill in the art would not have expected subcutaneous administration of clinically appropriate doses of exendin(9-39) to be therapeutically effective in the treatment of postprandial hyperinsulinemic hypoglycemia.

As detailed herein, it has been surprisingly shown that administration of exendin(9-39) by twice-per-day (BID) subcutaneous injection (SC) can effectively prevent hypoglycemia in patients having post-bariatric hyperinsulinemic hypoglycemia, that such prevention results at a dose of 30 mg or lower (e.g., in the range 7.5 mg-20 mg, e.g., 10 mg-15 mg), that such prevention can be achieved using a convenient administration schedule not necessarily tied to meal times, and that the pharmacokinetics of exendin(9-39) SC administration may be tuned based on the concentration of exendin(9-39) in the injectate, as well as by dose, to achieve an efficacious treatment. See Example 3 and Example 4. Thus, in one aspect, the present invention relates to pharmaceutical compositions and methods for subcutaneously administering exendin(9-39) at a BID dose in the range of about 7.5 mg-20 mg for the treatment and prevention of hyperinsulinemic hypoglycemia.

It will be recognized by physicians and pharmacologists that the present invention represents a significant advance in the field of surgical intervention for weight loss and/or metabolic control. This is especially important, because those post-bariatric patients currently suffering hypoglycemic excursions have no effective therapy and are sometimes critically ill. The intractable nature of the problem has been highlighted by those patients with disease so debilitating they reversed the surgery, or underwent other highly morbid procedures, such as partial pancreatectomy, only to learn the condition persists. The present invention provides a therapeutic intervention that can largely protect them should they suffer from post-bariatric hyperinsulinemia.

2. Definitions

The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In some cases, terms with commonly understood meanings are defined herein for clarity and/or for ready reference, and the inclusion of such definitions herein should not be construed as representing a substantial difference over the definition of the term as generally understood in the art.

Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. All technical and patent publications cited herein are incorporated herein by reference in their entirety.

All numerical designations, e.g., pH, temperature, time, concentration, and molecular weight, including ranges, are approximations which are varied (+) or (−) by increments of 0.1 or 1.0, as appropriate. It is to be understood, although not always explicitly stated, that all numerical designations are preceded by the term “about.” References to ranges include the end-points unless indicated otherwise. For example, administration of a dose of exendin(9-39) in the range 7.5 mg-15 mg includes administration of 7.5 mg or 15 mg.

The singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a compound” includes a plurality of compounds.

The term “comprising” is intended to mean that the compositions and methods include the recited elements, but not excluding others. “Consisting essentially of” shall mean excluding other elements that would materially affect the basic and novel characteristics of the claimed invention. “Consisting of” shall mean excluding any element, step, or ingredient not specified in the claim. Embodiments defined by each of these transition terms are within the scope of this invention.

“Exendin(9-39)” or “Ex(9-39)” or “Ex9” refers to a 31 amino acid peptide with an empirical formula of C₁₄₉H₂₃₄N₄₀O₄₇S and a molecular weight of 3369.8 Daltons. The amino acid sequence for exendin(9-39) is shown as follows: H-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH₂. Exendin(9-39) comprises residues 9-39 of the GLP-1 receptor agonist exendin-4 and is a GLP-1 receptor antagonist. See, Montrose-Rafizadeh et al., Journal of Biological Chemistry, 272:21201-21206 (1997). As used herein, the term “exendin(9-39)” encompasses pharmaceutically acceptable salts of exendin(9-39), including but not limited to sulfate, hydrochloride, phosophate, sulfamate, acetate, citrate, lactate, tartrate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate, cyclohexylsulfamate and quinate salts. In some embodiments, exendin(9-39) is in the form of exendin(9-39) acetate or exendin(9-39) trifluoroacetate. Where not otherwise specified herein, exendin(9-39) acetate is used (obtained from Bachem (Clinalfa, Laufelfingen, Switzerland)).

The abbreviation “GLP1A” refers to a GLP1 receptor antagonist (sometimes referred to as a “GLP1 antagonist”).

The terms “administer,” “administering,” and “administration,” as used herein, refer to introducing a compound (e.g., exendin(9-39)) or composition into a human subject. As used herein, the terms encompass both direct administration (e.g., administration to a subject by a medical professional or other caregiver, or by self-administration, or by programming an automatic device to deliver exendin(9-39) on a BID schedule) and indirect administration (e.g., the act of prescribing a compound or composition to a subject).

The terms “treatment,” “treating,” and “treat,” as used herein in reference to administering exendin(9-39) to treat hyperinsulinemic hypoglycemia, covers any treatment of a disease in a human subject, and includes: (a) reducing the risk, frequency or severity of hypoglycemic episodes in patients with a history of hyperinsulinemic hypoglycemia, (b) reducing the risk of occurrence of hypoglycemia in a subject determined to be predisposed to the disease, such as a person who has received post-bariatric surgery, but not yet diagnosed as having the disease, (c) impeding the development of the disease; and/or (d) relieving the disease, i.e., causing regression of the disease and/or relieving one or more disease symptoms.

As used herein, the term “injectate” refers the exendin(9-39)-containing composition subcutaneously delivered to a patient at a morning or evening administration. A morning or evening injectate is typically administered as a single injection (e.g., injection of a 0.7 ml volume). However an injectate can be delivered using more than one (e.g., two) injections, as may be done when the injectate volume is greater than comfortably tolerated as a single injection.

As used herein, “/kg” (e.g., 7,500 pmol/kg”) means “per kilogram patient body weight.”

3. Methods and Compositions for the Treatment of Hyperinsulinemic Hypoglycemia

In one aspect, the present invention provides methods and compositions for the treatment of hyperinsulinemic hypoglycemia by subcutaneous (SC) administration of a therapeutically effective dose of exendin(9-39).

3.1 Patient Population

In some embodiments, a patient to be treated according to the methods described herein is a patient having hyperinsulinemic hypoglycemia (HH). In certain embodiments, the patient having hyperinsulinemic hypoglycemia has previously had bariatric surgery (e.g., Roux-en-Y Gastric Bypass) and/or a related metabolic procedure. In certain embodiments, the patient has previously had bariatric surgery (e.g., Roux-en-Y Gastric Bypass) and/or a related metabolic procedure and is at risk for developing hyperinsulinemic hypoglycemia.

Patients with hyperinsulinemic hypoglycemia may be identified by any suitable method. In some embodiments, hyperinsulinemic hypoglycemia is diagnosed by the presence of Whipple's triad, which has the following criteria: (1) the occurrence of hypoglycemic symptoms; (2) documented low plasma glucose level at the type of the symptoms; and (3) resolution of the symptoms after plasma glucose is raised. In some embodiments, hyperinsulinemic hypoglycemia is defined by the occurrence of capillary glucose ≤50 mg/dL at least once per month by patient report or medical record. In some embodiments, hyperinsulinemic hypoglycemia is defined by a plasma glucose concentration of ≤55 mg/dL during an oral glucose tolerance test or meal tolerance test in association with inappropriately elevated plasma insulin (≥3 uU/mL) or c-peptide (>0.3 mg/dL) when glucose was ≤55 mg/dL. In some embodiments, hyperinsulinemic hypoglycemia is defined by a plasma glucose concentration of ≤60 mg/dL during an oral glucose tolerance test or meal tolerance test in association with inappropriately elevated plasma insulin (≥3 uU/mL) or c-peptide (>0.3 mg/dL) when glucose was ≤60 mg/dL.

“Hyperinsulinemic hypoglycemia,” as used herein, encompasses the conditions dumping syndrome, nesideoblastosis, noninsulinoma pancreatogenous hypoglycemia syndrome (NIPHS), and/or post-prandial reactive hypoglycemia. Hyperinsulinemic hypoglycemia may result from a gastric or bariatric procedure, such as a Roux-en-Y gastric bypass (RYGB), or may have a congenital, acquired, or induced origin.

In one embodiment, the patient treated has previously had a bariatric procedure and/or related metabolic procedure, such as a Roux-en-Y Gastric Bypass procedure. Bariatric and/or related metabolic procedures include, but are not limited to, Roux-en-Y Gastric Bypass, Vertical Sleeve Gastrectomy, placement of an endosleeve device, such as the EndoBarrier Gastrointestinal Liner System, also called an “endoluminal liner,” duodenal mucosal resurfacing, also referred to as duodenal ablation, partial bypass of the duodenum, involving duodeno-ileal or duodeno-jejunal anastomosis, vagal nerve blockade, and/or pyloroplasty).

A bariatric procedure (i.e., bariatric surgery) typically involves any of the foregoing: partially or completely bypassing the duodenum and/or decreasing nutrient exposure to the duodenum, increasing the rapidity of nutrient transit to the lower part of the intestines (often specifically the ileum), and/or otherwise increasing ileal nutrient exposure. Bariatric surgery may be intended for weight loss or metabolic benefit (such as resolution of diabetes), or both. Such weight loss or metabolic procedures, referred to herein as “bariatric procedures” may enhance secretion of GLP-1 from the distal small intestine, especially the ileum, leading to elevated insulin secretion, and in some patients hypoglycemia. The patient may be referred to as a “post bariatric surgery” patient or “post-RYGB.”

In another embodiment, the patient has previously had a related metabolic procedure. As but one example, in one embodiment, the patient treated has previously had a non-bariatric surgical procedure involving the gastrointestinal system (including but not limited to esophagectomy, for example for treatment of esophageal cancer, Nissen Fundoplication, for example for treatment of gastroesophageal reflux, or gastrectomy, for example for treatment of gastric cancer) and so may be referred to herein as “post gastrointestinal surgery.”

In another embodiment, the patient treated is prediabetic and/or insulin resistant and may benefit from prevention of pancreatic hyperstimulation from oral carbohydrate ingestion leading to post-prandial hypoglycemia. In another embodiment, a treated patient has a congenital, acquired, or induced form of hyperinsulinemic hypoglycemia, such as congenital hyperinsulinism or sometimes referred to as congenital nesidioblastosis.

In a preferred embodiment, however, the patient has had bariatric surgery to aid in weight loss and/or metabolic control and has suffered hypoglycemic excursions requiring urgent medical attention; such patients, as demonstrated conclusively in the examples below, can benefit markedly from treatment with a subcutaneously administered formulation of exendin(9-39) in accordance with the invention.

A typical adult patient with hyperinsulinemic hypoglycemia will present within 10 years of bariatric and/or other gastrointestinal surgery with symptoms of hypoglycemia (e.g. palpitations, tremor, weakness, sweating, confusion, fatigue, and/or blurred vision) within 5 hours of eating that are associated with a plasma glucose of ≤60 mg/dL and immediate resolution with carbohydrate intake. Many patients experience neuroglycopenic symptoms, such as altered mental status, loss of consciousness, or seizures. Hyperinsulinemia (>2 uU/mL or 13.9 pmol/L) may be documented in the proper laboratory setting at the time of the hypoglycemic event. However, documentation of hyperinsulinemia is not always possible due to logistical challenges associated with this testing (which involves induced hypoglycemia) and concerns over patient safety.

Physicians skilled in the art will recognize from this disclosure that the methods of the invention provide effective treatment, such that a physician following the same prescribing information herein can expect therapeutic benefit will be achieved in patients whom, for treatment of varying underlying conditions, have had surgical manipulation of the gastrointestinal anatomy, and resultant secondary hyperinsulinemic hypoglycemia.

Accordingly, to illustrate, the methods of the invention can be used to treat patients such as: 1) a patient whom, due to gastroesophageal reflux, underwent a Nissen Fundoplication procedure, and subsequently developed secondary hyperinsulinemic hypoglycemia; 2) a patient whom, due to a malignant gastric tumor (e.g. adenocarcinoma, gastrointestinal stromal tumor (GIST), or lymphoma), required partial or complete gastrectomy, with or without any of the foregoing gastric reconstructive procedures: Bilroth I, Bilroth II, RYGB, or Jejunal interposition, developed secondary hyperinsulinemic hypoglycemia; and 3) a patient whom, due to a tumor involving the esophagus or the esophageal gastric junction (EGJ), underwent an esophagectomy, developed secondary hyperinsulinemic hypoglycemia.

Those skilled in the art will further appreciate that patients with hypoglycemia due to endogenous, acquired, or congenital hyperinsulinism (“endogenous hyperinsulinemia” as used herein, refers to any such condition not caused by bariatric surgery or GI surgery) can benefit from application of the methods of the invention. Hypoglycemia in these instances can be severe, even life-threatening. Acquired hyperinsulinism may result from insulinomas, autoimmune syndromes, reactive hypoglycemia, adult nesidioblastosis, or gastric dumping syndrome (not due to bariatric or GI surgery). Congenital hyperinsulinism may manifest in the newborn period, or many years later. Accordingly, the methods and formulations of the invention include methods to treat such conditions. In the case of hyperinsulinemia resulting from an insulinoma and congenital hyperinsulinism, a sustained release formulation and/or an immediate release formulation that is administered continuously, such as via a subcutaneous pump, would be employed, with particular emphasis on the prevention of nocturnal hyperinsulinemia.

In similar fashion, hyperinsulinism may further be induced as a medicinal side-effect of, for example, a GLP-1 agonist, such as exenatide, liraglutide, lixisenatide, albiglutide, and dulaglutide. Accordingly, the methods and formulations of the invention include methods to treat overdoses with such drugs.

In some cases, patients with hyperinsulinemic hypoglycemia may also present with cumulative hyperinsulinemic hypoglycemia-associated cognitive impairment. Accordingly, the methods and formulations of the invention include methods to treat or prevent a worsening of cognitive impairment in such patients. Further, in pediatric and adult patients alike, acute and chronic hypoglycemia may be associated with morbidities not only such as cognitive impairment, but also depression, heart palpitations/tachycardia, and potentially other conditions, all of which may be reduced or prevented by preventing hypoglycemia by administration of a GLP1A, such as exendin(9-39), as described herein for post-bariatric patients suffering from hyperinsulinemia/hypoglycemia. In some diabetic patients, severe hypoglycemia has repeatedly been associated with increased total and cardiovascular mortality risk. Thus, prevention of severe hypoglycemia is an important clinical goal for both hospitalized and non-hospitalized patients, and the present invention provides methods and formulations useful for both groups of patients.

3.2 Treatment Parameters

In some embodiments, compositions comprising a therapeutically effective dose of the GLP1A, exendin(9-39), are administered to a patient in need thereof for the treatment or prevention of hyperinsulinemic hypoglycemia.

3.2.1. Administration Route

According to the invention, exendin(9-39) is administered by subcutaneous administration (e.g., subcutaneous injection). Sites of injection, include, but are not limited to, injection in the thigh, abdomen, upper arm region, or upper buttock region.

3.2.2 Administration Dose

As discussed in Examples below and elsewhere herein, patients with hyperinsulinemic hypoglycemia may be treated by BID SC administration of exendin(9-39) at therapeutically effective doses of 30 mg or lower (e.g., about 10 mg to 30 mg, 10 mg to 25 mg, 10 mg to 20 mg, 15 mg to 20 mg, 10 mg to 17.5 mg, and 10 mg to 15 mg). Exemplary doses include 10 mg, 12.5 mg, 15 mg, 17.5 mg, 20 mg, 22.5 mg, 25 mg, 27.5 mg or 30 mg. In some embodiments, the therapeutically effective amount of exendin(9-39) that is administered (e.g., in BID dosing) is selected from 10 mg, 15 mg, 17.5 mg, and 20 mg. In some embodiments, a therapeutically effective dose of exendin(9-39) or range of doses will vary depending upon the needs and physical attributes of the patient. It will be understood by a person of ordinary skill in the art that the doses described herein can be administered at varying concentrations, including but not limited to the injectate concentrations described in Section 3.2.4.1 below.

3.2.3 Administration Schedule

Advantageously, exendin(9-39) may be subcutaneously administered BID to treat hyperinsulinemic hypoglycemia. In some embodiments exendin(9-39) is subcutaneously administered QD.

3.2.3.1 BID Administration

BID (twice per day) administration is well known in the medical arts. In some embodiments BID doses are administered (e.g., self-administered) at about 12 hour intervals (e.g., 7 a.m. and 7 p.m.). However, shorter (e.g., 8 a.m. and 6 p.m.) or longer (e.g., 7 a.m. and 10 p.m.) intervals between administrations are possible provided the administrations are at least about 6 hours apart. Preferably the administrations are at least about 7 hours, 8 hours, 9 hours, 10 hours or 11 hours apart. Preferably the administrations are not more than about 15 hours apart.

3.2.3.2 Timing of Administration and Relationship to Meals

In one aspect of the invention, an immediate-release formulation of exendin(9-39) is provided as a subcutaneous injectable formulation that is administered prior to the administration of a meal. For example, in some embodiments, exendin(9-39) is administered within 60-150 minutes (e.g., within 90-120 minutes) prior to morning and evening meals (or before the two main meals of the day, approximately 6 hours or more apart). In some embodiments, exendin(9-39) is administered at least one hour prior to the morning meal. Using BID dosing 60-150 minutes (e.g., within 90-120 minutes) prior to the morning and evening meals, the peak GLP-1 plasma concentration occurring approximately 30-60 minutes post-meal will be countered by sufficient exendin(9-39) plasma concentrations at that time to prevent GLP-1 induced hyperinsulinemia.

In another embodiment the BID dosing will be a morning and evening administration with a morning administration after wakening in the morning and evening administration about 12 hours later (in some embodiments, about 12-14 hours, about 12-16 hours later, or about 9-15 hours later). The morning administration may be before or after the morning meal (breakfast). In this embodiment, the dosing schedule is independent of (i.e., not based on, or dictated by) the timing of meals. In some embodiments the morning administration is within a specified time before and/or after the morning meal (e.g. one hour before and/or one hour after breakfast). In some embodiments the morning administration is before or after the morning meal, as discussed above, and the evening administration is prior to retiring for the night (bedtime) such as between the evening meal and bedtime, or within 1, 2, or 3 hours of bedtime.

In a related embodiment the dosing schedule is semi-independent of mealtimes. For example, in the semi-independent schedule the morning dose is administered on a predetermined schedule relative to the morning meal and the evening dose is scheduled at a time independent of the time of the evening meal (e.g., about 12 hours after the morning administration without regard to the time of the evening meal).

Without intending to be bound by a specific mechanism, it is believed that the schedule, dose, route and formulations of the invention allow the evening administration to provide additional protection at breakfast, and the morning administration to provide protection during the day (e.g., lunch, dinner, or multiple small meals during the day). Advantageously, subcutaneous BID administration of a therapeutically effective dose of exendin(9-39) is protective even when not timed to coincide with meals. In contrast, as demonstrated in EXAMPLE 2, an IV bolus injection of 7,500 pmol/kg exendin(9-39) reversed hypoglycemia only if timed to coincide with the peak GLP-1 plasma concentrations. The dosing approaches set forth herein provides considerably more flexibility to the patient than alternative approaches, resulting in increased compliance and a superior quality of life for the patient.

3.2.4 Administration Formulation

3.2.4.1 Injectate Concentration and Volume

Surprisingly, certain pharmacokinetic parameters of SC BID exendin(9-39) administration can be modified by selecting the concentration of exendin(9-39) in the injectate. As described in the Examples, subcutaneous injection of a low concentration formulation results in a shorter Tmax (i.e., a faster rise to Cmax) relative to a higher concentration. Subcutaneous injection of a high concentration formulation results in a lower Cmax, a longer Tmax, and longer half-life relative to a lower concentration. See FIG. 7A and Table 4.

For purposes of this invention a concentration less than 20 mg/ml is a low concentration, e.g., 4-20 mg/ml, preferably about 10-20 mg/ml, and often about 8-16 mg/ml, most often about 13-16 mg/ml, and very often 15 mg/ml. The low concentration formulation results in a pharmacokinetic profile useful for BID administration. As shown in FIG. 7B and Table 5 (Example 3), subcutaneous administration of exendin(9-39) at varying doses but equivalent concentrations of about 13-16 mg/ml resulted in a favorable immediate release formulation with a Cmax greater than a preferred steady state plasma exendin(9-39) concentration of at least 100 ng/ml as measured by liquid chromatograph-mass spectrometry, at 10, 20 and 30 mg doses.

For purposes of this invention a concentration greater than about 20 mg/ml (e.g., 20-45 mg/ml) is considered a “high” concentration. As shown in FIG. 7A and Table 4, subcutaneous injection of a relatively more concentrated solution, for example in a range inclusive of and exceeding 20 mg/ml, e.g., 20-40 mg/ml, will result in a lower Cmax, with a longer half-life. For example, as shown in FIG. 7A and Table 4, subcutaneous administration of exendin(9-39) at a dose of about 20 mg and concentration of about 24 mg/ml exhibited a significantly longer half-life than subcutaneously administered exendin(9-39) at a dose of about 10 mg and concentration of about 16 mg/ml (9.14 hours vs. 3.60 hours). In some embodiments, a more highly concentrated solution of exendin(9-39) results in an exendin(9-39) plasma Cmax that is lower than a relatively lower concentration formulation but which is still greater than a preferred steady state plasma exendin(9-39) concentration of 70 ng/ml or greater (e.g., as shown in FIG. 7A and Table 4 for the “10X” (approximately 20 mg) dose as compared to the “5X” (approximately 10 mg) dose). Thus, a more concentrated solution may be more amenable to less frequent dosing, e.g., QD dosing, or to BID dosing that is not tied to meals.

In some embodiments, exendin(9-39) is subcutaneously administered at a concentration of about 4-25 mg/ml, about 4-20 mg/ml, about 10-25 mg/ml, about 10-20 mg/ml, about 10-18 mg/ml, about 8-16 mg/ml, about 12-20 mg/ml, about 10-15 mg/ml, or about 13-16 mg/ml (e.g., about 4 mg/ml, about 5 mg/ml, about 6 mg/ml, about 7 mg/ml, about 8 mg/ml, about 9 mg/ml, about 10 mg/ml, about 11 mg/ml, about 12 mg/ml, about 13 mg/ml, about 14 mg/ml, about 15 mg/ml, about 16 mg/ml, about 17 mg/ml, about 18 mg/ml, about 19 mg/ml, about 20 mg/ml, about 21 mg/ml, about 22 mg/ml, about 23 mg/ml, about 24 mg/ml, or about 25 mg/ml).

In some embodiments, exendin(9-39) is subcutaneously administered at a concentration in the range of about 13 mg/ml to about 16 mg/ml. In some embodiments, exendin(9-39) is subcutaneously administered at a concentration of about 15 mg/ml.

As shown in FIG. 7B and Table 5, both a relatively lower dose of 10 mg and a relatively higher dose of 30 mg yielded a Cmax greater than the preferred steady state plasma exendin(9-39) concentration of 70 ng/ml or greater and were efficacious in reversing hyperinsulinemic hypoglycemia when administered at approximately equal concentrations in the range of about 13-16 mg/ml. Thus, in one aspect, a relatively lower dose of exendin(9-39) (e.g., a dose of about 5-10 mg, e.g., about 5 mg, about 7.5 mg, or about 10 mg) can be efficacious in treating hyperinsulinemic hypoglycemia by adjusting the exendin(9-39) solution to an appropriate concentration as described herein. In some embodiments, a relatively lower dose of exendin(9-39) (e.g., a dose of about 5-10 mg, e.g., about 5 mg, about 7.5 mg, or about 10 mg) is administered at a concentration of at least about 10 mg/ml, e.g., at a concentration in the range of about 13-16 mg/ml, e.g., at a concentration of about 15 mg/ml.

Generally exendin(9-39) is subcutaneously administered at a concentration sufficient to result in a steady state plasma exendin(9-39) concentration of at least 70 ng/ml, at least 100 ng/ml, or at least 150 ng/ml as measured by liquid chromatograph-mass spectrometry. In some embodiments, exendin(9-39) is subcutaneously administered at a concentration sufficient to result in a steady state plasma exendin(9-39) concentration of about 100-200 ng/ml. In some embodiments, exendin(9-39) is subcutaneously administered at a concentration sufficient to result in a steady state plasma exendin(9-39) concentration of at least 70 ng/ml up to 250 ng/ml.

Table A below provides exemplary therapeutically effective exendin(9-39) formulations:

TABLE A Exendin(9-39) Concentration 1 10-30 mg 10-25 mg/mL 2 10-30 mg 10-20 mg/mL 3 10-30 mg 10-18 mg/mL 4 10-30 mg 13-16 mg/mL 5 10-25 mg 10-25 mg/mL 6 10-25 mg 10-20 mg/mL 7 10-25 mg 10-18 mg/mL 8 10-25 mg 13-16 mg/mL 9 10-20 mg 10-25 mg/mL 10 10-20 mg 10-20 mg/mL 11 10-20 mg 10-18 mg/mL 12 10-20 mg 13-16 mg/mL 13 10-15 mg 10-25 mg/mL 14 10-15 mg 10-20 mg/mL 15 10-15 mg 10-18 mg/mL 16 10-15 mg 13-16 mg/mL 17 15-30 mg 10-25 mg/mL 18 15-30 mg 10-20 mg/mL 19 15-30 mg 10-18 mg/mL 20 15-30 mg 13-16 mg/mL 21 15-25 mg 10-25 mg/mL 22 15-25 mg 10-20 mg/mL 23 15-25 mg 10-18 mg/mL 24 15-25 mg 13-16 mg/mL 25 15-20 mg 10-25 mg/mL 26 15-20 mg 10-20 mg/mL 27 15-20 mg 10-18 mg/mL 28 15-20 mg 13-16 mg/mL

In some embodiments, each administration of a BID subcutaneous administration of exendin(9-39) results in an exendin(9-39) Cmax of at least 100 ng/ml. In some embodiments, for example for patients having relatively higher GLP-1 levels or having greater beta-cell sensitivity to GLP-1, each administration of a BID subcutaneous administration of exendin(9-39) results in an exendin(9-39) Cmax of at least 150 ng/ml.

In some embodiments, the exendin(9-39) injectate comprises an exendin (9-39) dose and concentration that, when administered, results in steady state plasma exendin(9-39) concentration of at least 70 ng/ml, preferably at least 100 ng/ml, or even more preferably at least 150 ng/ml, as measured by LCMS. In some embodiments, the exendin(9-39) formulation has such a dose and concentration that results in steady state plasma exendin(9-39) concentration of 100-250 ng/ml, e.g., 100-200 ng/ml, 100-150 ng/ml, or 150-200 ng/ml.

In some embodiments, each dose is administered in a total volume ranging from 0.25-2 ml injectate, with most patients administering an injection volume ranging from 0.5-1.5 ml, e.g., 0.7-1 ml.

3.2.4.2 Injectate Formulation

Exendin(9-39) may be administered in any pharmaceutically acceptable form. In some embodiments, exendin(9-39) is formulated with a pharmaceutically acceptable diluent or carrier that is suitable for subcutaneous administration. Examples of pharmaceutically acceptable diluents or carriers include, but are not limited to, water, saline, and isotonic buffer solutions. In some embodiments the injectate formulation further comprises one or more additional excipients such as preservatives and pH adjustment agents.

In one approach exendin(9-39) is formulated in normal saline (0.9% saline). In one approach the exendin(9-39) is formulated with an antimicrobial preservative, a tonicity-adjusting agent, such as mannitol, and/or a buffer (e.g., to bring the solution to a pH of about 4-5).

As shown in Example 3 and FIG. 7A, administration of a lower dose (10 mg, or “5 x”) resulted in a higher exendin(9-39) Cmax than higher doses formulated in the same volume of solution (i.e., having a higher concentration). Without intending to be bound by a particular mechanism, this may be a result of aggregation (e.g., dimer or higher multimer formation). Thus, in one approach exendin(9-39) is formulated with an agent to reduce aggregation or dimer formation such as a surfactant (e.g., a non-ionic surfactant, such as a polysorbate or a poloxamer), polyol, or sugar, or by optimizing the pH and/or ionic strength of the solution.

In one aspect, exendin(9-39) is formulated for immediate release. In one approach, exendin(9-39) is formulated as an injectable, immediate-release formulation of exendin(9-39) using a formulation that is used to deliver exenatide, marketed as BYETTA™ (see U.S. Pat. Nos. 5,424,286; 6,858,576; 6,872,700; 6,902,744; 6,956,026; 7,297,761; 7,521,423; and 7,741,269, incorporated herein by reference).

In another aspect, exendin(9-39) is formulated for extended release, i.e., an extended release formulation, such that, when administered, the formulation ensures that the active drug product has a lasting presence in the blood throughout the targeted time period in the course of treatment. Use of these formulations and methods allows plasma glucose homeostasis to be maintained with fewer subcutaneous injections, relative to immediate release formulations. In some embodiments, exendin(9-39) is formulated with microspheres or nano-lipocapsules, which provide for sustained and extended release profiles. In some embodiments, exendin(9-39) is formulated with slowly eroding microspheres. Such microspheres include, for example and without limitation, those made with a biopolymer, such as Poly (lactic-co-glycolic acid) (PLGA) or its equivalent. Such formulations provide for release of drug over an extended period of time (1-10 weeks). To prepare the formulation, exendin(9-39) is loaded into the microspheres, and the formulation provides that exendin is steadily released over time as the matrix materials degrade. These microspheres can be formulated to minimize drug bursts and maintain a steady release profile. In some embodiments, exendin(9-39) is encapsulated into nano-lipocapsules to prepare another formulation of the invention, which provides similar sustained and extended drug release. These formulations are provided in a variety of particle and capsule sizes and compositions, providing the physician a variety of rapid, medium, and slow release profile formulations to optimize therapy for individual patients.

In one approach, exendin(9-39) is formulated as an injectable, extended-release formulation of exendin(9-39) using a formulation that is used to deliver exenatide, marketed as BYDUREON™ (see U.S. Pat. Nos. 5,424,286; 6,479,065; 6,495,164; 6,667,061; 6,824,822; 6,858,576; 6,872,700; 6,956,026; 7,223,440; 7,456,254; 7,563,871; 7,612,176; 7,741,269; 8,216,180; 8,329,648; 8,431,685; 8,439,864; 8,461,105; and 8,906,851, incorporated herein by reference).

In another approach, exendin(9-39) is formulated using a formulation that is used to deliver liraglutide, delivered in a daily dose, marketed as Victoza™ (see U.S. Pat. Nos. 6,004,297; 6,268,343; 6,458,924; 7,235,627; 8,114,833; and 8,846,612).

Other formulations of the invention having a variety of different features and advantages may be made in accordance with the teachings of U.S. Pat. Nos. 8,445,647; 8,895,033; 8,969,293; 8,299,025; and 8,546,326; and U.S. Patent Application Publication Nos. 2015/0258016; 2015/0238568; 2015/0057227; 2015/0056285; 2014/0309168; 2014/0256626; 2013/0252894; 2013/0195939; and 2013/0172250, incorporated herein by reference, substituting exendin(9-39) for the active pharmaceutical ingredient described.

In some embodiments, exendin(9-39) is formulated as a sterile, preserved isotonic solution in a unit or multi-dose glass vial or ampule for administration with the use of a syringe, similar to the glucagon emergency kit. In some embodiments, the exendin(9-39) is provided as an injectable suspension in a single-dose tray containing a vial of exendin(9-39), a vial connector, a prefilled diluent syringe, and one or more needles.

In some embodiments, exendin(9-39) is formulated as a sterile, preserved isotonic solution in a glass cartridge pen-injector device. Such compositions, for example and without limitation contain 5-30 mg of exendin(9-39), an appropriate volume of an antimicrobial preservative, a tonicity-adjusting agent, such as mannitol, and a buffer to bring the solution to a pH of about 4-5.

In some instances, the formulation of exendin(9-39) is provided as an injectable suspension in a single-dose pen containing exendin(9-39), a diluent, and one or more needles. In some instances, microneedles coated with or containing the formulation of exendin(9-39) are used.

In some embodiments, exendin(9-39) is formulated as a sterile, preserved isotonic solution in a glass cartridge pen-injector device. Such compositions, for example and without limitation contain 5-30 mg of exendin(9-39), an appropriate volume of an antimicrobial preservative, a tonicity-adjusting agent, such as mannitol, and a buffer to bring the solution to a pH of about 4-5.

3.2.5 Different Evening and Morning Injectates

In some embodiments, twice-per-day administration comprises administering a morning injectate and an evening injectate that contain different exendin(9-39) doses and/or different concentrations of exendin(9-39). Generally, each of the injectates has an exendin(9-39) amount and concentration within the ranges described herein. However, in this embodiment, the amount of exendin(9-39) in the evening administration is greater than the amount in the morning injectate and/or the exendin(9-39) concentration in the evening injectate is greater than the concentration of exendin(9-39) in the morning injectate. In some embodiments the two injectates will have different quantities, the same concentration, of. In some embodiments the two injectates will have the same amount of exendin(9-39) but different concentration. In some embodiments both the concentration and amount of exendin(9-39) will be different.

Without intending to be bound by a particular mechanism, the increased amount of exendin(9-39) administered in the evening may provide higher exendin(9-39) levels at the time of the morning meal. Without intending to be bound by a particular mechanism, the increased concentration of exendin(9-39) is expected to result in a more “flat” plasma concentration profile, including a longer time to Tmax, for a more sustained effect at the time of the morning meal.

In some embodiments the amount of exendin(9-39) in the evening injectate is 5 mg to 10 mg greater than the amount in the morning injectate. In some embodiments the amount of exendin(9-39) in the evening injectate is 5 mg greater than the amount in the morning injectate. In some embodiments the amount of exendin(9-39) in the evening injectate is 10 mg greater than the amount in the morning injectate. In some embodiments the amount of exendin(9-39) in the morning injectate is 10 mg, 15 mg, or 20 mg.

In some embodiments the concentration of exendin(9-39) in the evening injectate is 5 mg/ml-10 mg/ml greater than the amount in the morning injectate. In some embodiments the concentration of exendin(9-39) in the evening injectate is about 5 mg/ml greater than the amount in the morning injectate. In some embodiments the concentration of exendin(9-39) in the evening injectate is about 10 mg/ml greater than the amount in the morning injectate. In some embodiments the concentration of exendin(9-39) in the morning injectate is 10-16 mg/ml and the concentration of exendin(9-39) in the evening injectate is higher and is in the range of 15-20 mg. In some cases, the amount of exendin(9-39) in the evening injectate is 5 mg-10 mg greater than the amount in the morning injectate. In some such cases the amount of exendin(9-39) in the morning injectate is 10 mg and the amount in the evening injectate is 15 mg. In some such cases the amount of exendin(9-39) in the morning injectate is 10 mg and the amount in the evening injectate is 20 mg. In some such cases the amount of exendin(9-39) in the morning injectate is 15 mg and the amount in the evening injectate is 20 mg. In some such cases the amount of exendin(9-39) in the morning injectate is 15 mg and the amount in the evening injectate is 25 mg. In some such cases the amount of exendin(9-39) in the morning injectate is 20 mg and the amount in the evening injectate is 25 mg. In some such cases the amount of exendin(9-39) in the morning injectate is 20 mg and the amount in the evening injectate is 30 mg.

In some cases, the concentration of exendin(9-39) in the morning injectate is not the same as the concentration of exendin(9-39) in the evening injectate. For example, in one approach the concentration of exendin(9-39) in morning injectate is 15 mg/ml and the concentration of exendin(9-39) in the evening injectate is 20 mg/ml.

In some cases the exendin(9-39) amount and concentration of the morning and evening injectates are selected such that the exendin(9-39) Tmax after the evening administration is longer than the Tmax after the morning administration.

In one approach, the evening injectate is prepared or formulated to favor multimerization (e.g., dimerization) or precipitation of the exendin(9-39). Administration of the injectate at bedtime can delay absorption, producing a slower release profile compared to the morning administration, resulting in an advantageous basal morning level of at least 30 ng/mL Methods for preparing compositions comprising multimerized proteins are known. For example, the addition of a basic protein, such as protamine, to the exendin(9-39) preparation can favor formation of multimer peptide configurations. Alternatively, multimerization can be achieved by precipitating the exendin(9-39) out of solution, for example through the addition of salts, such as zinc salts, such that the molar ratio of the salt with respect to exendin(9-39) is greater than 1, so as to reduce the solubility of exendin(9-39) in a neutral solvent. In this approach, raising the pH (for example to 7.4), in the presence of such salts, can be used to favor precipitation of the peptide. Thus, in some embodiments the level of aggregation or multimerization in the evening injectate is greater than the level in the morning injectate. In some embodiments the exendin(9-39) is in a less soluble form in the evening injectate compared to the morning injectate.

3.2.6 Duration of Therapy

Patients may receive therapy for a predetermined time, an indefinite time, or until an endpoint is reached. Treatment may be continued on a continuous daily or weekly basis for at least two to three months, six months, one year, or longer. In some embodiments, therapy is for at least 30 days, at least 60 days, at least 90 days, at least 120 days, at least 150 days, or at least 180 days. In some embodiments, treatment is continued for at least 6 months, at least 7 months, at least 8 months, at least 9 months, at least 10 months, at least 11 months, or at least one year. In some embodiments, treatment is continued for the rest of the patient's life or until administration is no longer effective in maintaining normal plasma glucose levels to provide meaningful therapeutic benefit. In some embodiments, adult patients (60-100 kg or more) will receive therapeutic benefit from a single dose of exendin(9-39).

3.3 Delivery Devices

Devices such as injectable pen devices and pumps suitable for subcutaneous injections are well known. Such devices may be used to deliver the exendin(9-39) formulations described hereinabove according to the methods described herein.

3.3.1 Injectable Pen Device

In some embodiments, exendin(9-39) is administered using an injectable pen device that may be pre-programmed to deliver a fixed dosage amount. In some embodiments, the device is pre-programmed to deliver a fixed dosage ranging from 5-30 mg, e.g., 10-20 mg, or 7.5-15 mg, depending upon the needs and physical attributes of the patient. In some embodiments, the exendin(9-39) is formulated as an immediate release preparation, and is packaged, for example, in the form of a single or dual-chamber pen device (e.g., a 1 to 5 mL dual chamber pen—either a disposable pen or one that reloads disposable cartridges).

The drug product can be supplied as a freeze-dried lyophilized powder, stored in a 1 to 3 mL or larger, e.g., 5 mL, dual-chamber cartridge that is compatible with a disposable pen injector (see, for example, the Ypsomed dual chamber cartridge/pen injector: www.ypsomed.com/yds/products/dual-chamber-pens.html). Dose strengths can be conveniently made available to patients, including for example doses in the range of 5-30 mg of exendin(9-39), to be reconstituted in a volume of 0.25-2.0 ml normal saline per dose, or other pharmaceutically acceptable diluent suitable for subcutaneous administration.

In some embodiments, the drug product is supplied as individual injectable pen devices that are pre-programmed to deliver a fixed dosage amount, in which the morning dosage amount and the evening dosage amount are different amounts and/or concentrations. For example, in some embodiments, a first pen (e.g., for morning administration) delivers a dose in the range of 5-15 mg (e.g., a dose of 5 mg, 7.5 mg, 10 mg, 12.5, or 15 mg) and a second pen (e.g., for evening administration) delivers a higher dose in the range of 15-20 mg (e.g., a dose of 15 mg, 17.5 mg, or 20 mg). In some embodiments, the first pen delivers a dose of 10 mg and the second pen delivers a dose of 15 mg. In some embodiments a first pen delivers a dose of 15 mg and the second pen delivers a dose of 20 mg.

In another aspect, the present invention provides kits comprising individual injectable pen devices as described herein. In some embodiments, a kit comprises a plurality of individual injectable pen devices (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10 or more pens in a kit). In some embodiments, the kit comprises two or more individual injectable pen devices that are pre-programmed to deliver a fixed dosage amount, in which the morning dosage amount and the evening dosage amount are different amounts and/or concentrations. For example, in some embodiments, the kit comprises a first pen (e.g., for morning administration) that delivers a dose in the range of 5-15 mg (e.g., a dose of 5 mg, 7.5 mg, 10 mg, 12.5, or 15 mg) and further comprises a second pen (e.g., for evening administration) that delivers a higher dose in the range of 15-20 mg (e.g., a dose of 15 mg, 17.5 mg, or 20 mg). In some embodiments, the kit comprises a first pen that delivers a dose of 10 mg and a second pen that delivers a dose of 15 mg. In some embodiments, the kit comprises a first pen that delivers a dose of 15 mg and a second pen that delivers a dose of 20 mg.

3.3.2 Subcutaneous Pump

In one embodiment, the methods of the invention comprise the use of a subcutaneous pump, and the invention provides such pumps containing exendin(9-39) formulated as described herein for subcutaneous delivery. This methodology is generally very convenient for the patient. Compositions for such methods provided by the invention include solution formulations and freeze dried lyophilized powder for reconstitution. See, e.g., Kumareswaran et al., Discovery Medicine, 2012, 13:159-170, incorporated by reference herein.

3.4 Treatment Outcomes

In some embodiments, patients treated with the compositions and methods described herein exhibit an improvement in one or more symptoms of hypoglycemia, including but not limited to neuroglycopenic symptoms, beta-adrenergic symptoms, or plasma glucose levels.

In some embodiments, treatment in the typical adult or pediatric patient refers to treatment such that the postprandial plasma glucose nadir is maintained above a concentration of approximately 55 mg/dl (3.0 mmol/liter) based upon the Endocrine Society's Clinical Guidelines (Journal of Clinical Endocrinology & Metabolism, 2009, 94(3):709-728), and symptoms of hypoglycemia are reduced. Ideally, normal plasma glucose concentrations are maintained, with those skilled in the art recognizing that in humans a blood glucose level of 65 mg/dl or greater is preferred.

In some embodiments, treatment in a patient refers to treatment such that at least a 15% increase in postprandial plasma glucose nadir is achieved relative to baseline (e.g., before the onset of treatment). In some embodiments, treatment in a patient refers to treatment such that for a patient having a postprandial plasma glucose nadir ≤50 mg/dl at baseline (e.g., before the onset of treatment), an increase in postprandial plasma glucose nadir to ≥55 mg/dl is achieved relative to baseline.

Plasma glucose nadir can be measured, for example, by oral glucose tolerance test (OGTT) or meal tolerance test (MTT) as described herein. In some embodiments, treatment in a patient refers to treatment such that a statistically significant decrease in the severity of one or more symptoms of hypoglycemia overall during a OGTT or MTT and/or of neuroglycopenic symptoms elicited during the glucose “fall” period of OGTT or MTT is achieved relative to baseline (e.g., before the onset of treatment).

3.5 Dosage Escalation

Some physicians may desire to treat with a low or initiating (starting) dose (e.g., 5-7.5 mg), escalate to an increased if the initiating dose does not result in acceptable glycemic control, and maintain the initiating dose if glycemic control is sufficient.

In some embodiments, a starting dose of 10 mg exendin(9-39) in a morning dose and 10 mg exendin(9-39) in an evening dose is administered to the subject. If this dose does not result in sufficient coverage in the morning (e.g., does not result in sufficient glycemic control at the time of the morning meal), the evening dose may be increased, e.g., to 15 mg exendin(9-39) as the evening dose. In some embodiments, a starting dose of 15 mg exendin(9-39) in a morning dose and 15 mg exendin(9-39) in an evening dose is administered to the subject. If this dose does not result in sufficient coverage in the morning, the evening dose may be increased, e.g., to 20 mg exendin(9-39) as the evening dose.

These and other benefits of the invention will be appreciated in greater depth upon contemplation of the examples below and accompanying figures, which demonstrate that administration of exendin(9-39) as described herein can provide immediate and significant benefit to post-bariatric patients suffering hypoglycemic excursions after consuming normal amounts of glucose. Based upon American Society of Metabolic and Bariatric Surgery (ASMBS) recommendations (see asmbs.org/patients/life-after-bariatric-surgery), post-bariatric surgery patients are encouraged to limit their carbohydrate intake to 50 grams per day or less. Patients in the examples provided were administered 75 grams of carbohydrate within a 20 minute period of time, amounting to 1.5-fold the total ASMBS recommended daily intake. Thus, based upon the success demonstrated in the examples wherein administration of exendin(9-39) prevented hypoglycemia and markedly improved symptoms after a high carbohydrate load, under ordinary conditions, similar or greater efficacy would be anticipated.

4. Examples 4.1 Example 1: Continuous IV Infusion of Exendin(9-39) Effectively Reverses Hyperinsulinemic Hypoglycemia and Associated Symptoms

A randomized placebo-controlled blinded cross-over Phase 1 study was conducted to determine whether continuous IV infusion of exendin(9-39) can effectively reverse hyperinsulinemic hypoglycemia and associated symptoms. Exendin(9-39) was acquired as a lyophilized peptide: exendin(9-39) acetate 10 mg/vial from Bachem (Clinalfa, Laufelfingen, Switzerland). For preparation of the IV infusate, lyophilized exendin(9-39) was solubilized with 20 ml 0.9% normal saline (NS) for every 10 mg peptide, then diluted in 100 ml 0.9% NS and 50 ml of 25% human serum albumin, in a PVC-free, DEHP-free 1L infusion bag. The bag was covered with an opaque IV bag cover to aid with blinding. An identical-appearing bag was prepared, constituting the placebo infusate, containing the same volume of infusate (NS only) without the presence of peptide or albumin Eight patients with hyperinsulinemic hypoglycemia were randomized to receive an infusion of placebo and an infusion of exendin(9-39) in cross-over design during an oral glucose tolerance test (OGTT) on two separate days separated by no greater than 2 weeks. Patients were asked to fast for 12 hours prior to the infusion of study drug or placebo, and infusions and OGTTs were carried out the Center for Translational Research Unit (CTRU) at Stanford University. On the day of admission to CTRU, 2 IV lines were placed for infusion of study drug and blood collection. Fasting blood was drawn at T-40 minutes. At T-30 minutes, an IV bolus of 7,500 pmol/kg exendin(9-39) or placebo was administered over 1 minute, while a continuous IV infusion of exendin(9-39) at a rate of 500 pmol/kg/min (providing an infusion dose of about 0.35 mg/kg) or placebo (0.9% saline) was initiated and run for 210 minutes. At T+0 minutes an OGTT was initiated, wherein patients were instructed to consume a 75 g glucola drink over 20 minutes.

Plasma samples were collected at T-40, T+0, T+30, T+45, T+60, T+90, T+105, T+120, T+150, T+180 and at each timepoint immediately taken to the laboratory for processing. The following assays were then conducted: glucose, insulin, GLP-1, GIP, glucagon, and exendin(9-39). If glucose levels dropped to 50 mg/dL or less, the test was stopped and investigators intervened as needed to normalize glucose. At T-40 and concomitant with timed blood draws, a graded symptom questionnaire was completed repetitively by patients. This questionnaire was adapted from two validated hypoglycemia assessment tools, by segregating symptoms into three clear factors: autonomic, neuroglycopenic, and malaise, and then by adding a severity gradation scale, such that patients rated the severity of each reported symptoms from 1-5 (1: least severe; 5: most severe).

As shown in FIG. 1B and Table 1, patients exhibited an average glucose nadir of approximately 80 mg/dL during exendin(9-39) infusion, as compared to a nadir of <50 mg/dL during placebo infusion. Patients also exhibited a marked decrease in plasma insulin concentrations during exendin(9-39) infusion (see FIG. 1A and Table 1).

Metabolic responses, including plasma GLP-1, GIP, and glucagon responses, were measured as shown in FIGS. 2A-C, and Table 2. Although area under the curve (AUC) values were calculated as shown in Tables 1 and 2, the presentation of the data graphically, as presented in FIGS. 1 and 2, is more informative because subject OGTTs were stopped prematurely if they became hypoglycemic (as they did in 100% of cases during placebo infusion). For calculation of AUC in cases of premature cessation of the OGTT, the last value was carried forward. Patients were also assessed for hypoglycemic symptoms during exendin(9-39) infusion vs. placebo infusion. As shown in FIG. 3, continuous exendin(9-39) infusion substantially improved symptoms of hypoglycemia, as demonstrated by the dramatically reduced total hypoglycemic symptom assessment score. Additionally, to isolate symptoms associated with glucose rise and fall, two subscores were included: the “Glucose Fall” score, which encompasses symptoms associated with the fall in glucose to nadir, and the “Glucose Rise” score, which encompasses symptoms associated with the rise in glucose to peak.

The results demonstrate that continuous IV infusion of exendin(9-39) effectively reverses hyperinsulinemic hypoglycemia and associated symptoms.

4.2 Example 2: Single IV Bolus Injection of Exendin(9-39) Reverses Hypoglycemia Only if Timed Coincide with Peak GLP-1 Plasma Concentrations

A trial was performed to assess whether a single bolus dose of exendin(9-39) was able to prevent hypoglycemia in a 75 gram OGTT with subjects with hyperinsulinemic hypoglycemia. Two subjects with hyperinsulinemic hypoglycemia were admitted to the research clinic after a 12 hour overnight fast. An IV bolus of 7,500 pmol/kg exendin(9-39) was prepared as in Example 1. The subjects consumed a 75 gram glucola at T=0. GLP-1 levels are predicted to peak about 60 min after the administration of glucola (see, Myint et al., European Journal of Endocrinology, 2012, 166:951-955; see also FIG. 4D). After consuming the glucola, the subjects were infused intravenously with an IV bolus of exendin(9-39) over 1 minute, with the timing of the IV bolus administration relative to the 75 gram OGTT altered on different days, as follows: T=0, T+20, and T+50. Plasma was assayed at T-40, T+0, T+30, T+45, T+60, T+90, T+105, T+120, T+150, T+180 and at each timepoint immediately taken to the laboratory for processing. Measurements were taken for glucose, insulin, GLP-1, GIP, glucagon, and exendin(9-39). Bioavailability/PK profile of IV exendin(9-39) was evaluated by Cmax, Tmax, AUC0_(−∞), AUClast, VZ, CL, and T_(1/2). Exendin(9-39) concentration was measured by radioimmunoassay (RIA) as described in Kielgast et al., Diabetes, 2011, 60:1599-1607.

As shown in FIGS. 4A-C, dosing of the IV bolus of exendin(9-39) at 0 minutes or 20 minutes following administration of glucola did not prevent hypoglycemia, whereas dosing at 50 minutes after administration of glucola did prevent hypoglycemia. See, figure legend. FIGS. 4A-D demonstrates that peak plasma exendin(9-39) concentrations in the range of 500-600 nMol/L by radioimmunoassay at the time of peak plasma GLP-1 concentrations are required to avoid a glucose nadir below 50 mg/dL. The results shown in FIG. 4A-D suggest that in the absence of continuous IV infusion, or in the absence of an IV bolus timed precisely to the peak predicted GLP-1 plasma concentrations, hypoglycemia cannot be averted.

Exendin(9-39) plasma levels can be measured using a radioimmunoassay (RIA) generally as described in Kielgast et al., Diabetes, 2011, 60:159-1607. Exendin(9-39) plasma levels can be measured using liquid chromatography—mass spectrometry (LCMS) methodology generally as described in Lasaosa et al., J. Chromatogr B Analyt Technol Biomed Life Sci, 2014, 0:186-191. We refer to both methods in the discussion herein, and both methods are used in the scientific literature. We observed that measurement of plasma exendin(9-39) values using RIA were significantly higher than values determined using LCMS. We believe the LCMS values are more accurate. For definitional purposes, a claimed exendin(9-39) concentration (e.g., Cmax) refers to the absolute quantity of Exendin(9-39) which may be determined by LCMS or another equally quantitative method.

FIG. 5A depicts an average of eight patients' plasma exendin(9-39) concentrations at various timepoints following a 7,500 pmol/kg IV bolus of exendin(9-39) at T-30 minutes, followed by continuous IV fusion at a rate of 500 pmol/kg/min over 210 minutes as described in Example 1. See graph line with error bars. It has also been reported that in healthy subjects an intravenous infusion of exendin(9-39) at 500 pmol/kg/min fully reverses the glucose lowering effect of GLP-1. See, Edwards et al., Diabetes, 1999, 48:86-93. Based on the measured plasma exendin(9-39) concentrations as shown in FIG. 5A, a steady plasma exendin(9-39) concentration of approximately 500 nmol/L (as measured by radioimmunoassay) or of approximately 140 nmol/L (as measured by LCMS) is presumed to be required for efficacy.

FIG. 5A also shows the projected exendin(9-39) plasma concentration that would be expected from administering a single IV bolus of 7,500 pmol/kg exendin(9-39) at T-30 minutes. As previously reported, the half-life of a single dose of intravenously administered exendin(9-39) is about 33.5 minutes (see, Edwards et al., Diabetes, 1999, 48:86-93). Extrapolating from the exendin(9-39) concentration measured at T=0 (about 300 nmol/L as measured by RIA) it was concluded that the exendin concentration at T=−30 is about 600 nmol/L given the half-life of intravenously administered exendin(9-39). In view of the projected pharmacokinetic response for exendin(9-39) and the time course of the development of hypoglycemia following a meal (typically 1-3 hours after meals, with peak GLP-1 levels expected at about 60 minutes after the meal), a single IV bolus dose administered prior to or with a meal would likely not be effective for treatment of hyperinsulinemic hypoglycemia, because the exendin(9-39) plasma concentration would be expected to be very low at the predicted time of peak GLP-1 levels. Furthermore, even if an IV bolus having a higher dose of exendin(9-39) were administered, it would be expected to exhibit similar pharmacokinetic properties of a short half-life and rapid elimination from plasma. In view of the time course for the development of hypoglycemia and the lag between the time of a meal and the projected peak GLP-1 levels, even an IV bolus having a higher dose of exendin(9-39) would not be expected to be efficacious in averting hypoglycemia unless precisely timed with predicted peak plasma GLP-1 levels.

4.3 Example 3: A Single Dose of Subcutaneously Injected Exendin(9-39) Effectively Reverses Hyperinsulinemic Hypoglycemia and Associated Symptoms

As described above in Example 1, it was found that an IV bolus of 7,500 pmol/kg exendin(9-39) plus a continuous IV infusion of exendin(9-39) at a rate of 500 pmol/kg/min over 210 minutes was efficacious in reversing hyperinsulinemic hypoglycemia and associated symptoms. For the peptide exenatide, it has been reported that the absorption kinetics of exenatide in rats most closely approximates human absorption kinetics. See, Chen et al., Interspecies Modeling Pharm Res., 2013, 30:751-760. Rat intravenous and subcutaneous dose escalation pharmacokinetic data predicts that in humans, the Cmax of subcutaneously administered exendin(9-39) would be substantially lower than the Cmax of intravenously administered exendin(9-39). Accordingly, it was expected that a higher dose of exendin(9-39) would be needed for subcutaneous administration, as compared to intravenous administration, in order for exendin(9-39), to be effective in reversing hyperinsulinemic hypoglycemia.

To compare the pharmacokinetic parameters of intravenously or subcutaneously administered exendin(9-39), a single IV bolus of 7,500 pmol/kg exendin(9-39) or a single subcutaneous injection of 7,500 pmol/kg exendin(9-39) was administered in one subject on two separate days. The IV bolus consisted of 0.025 mg/kg of lyophilized exendin(9-39) (which equates to a dose of approximately 2 mg for an 80 kg patient) solubilized in 20 ml per 10 mg exendin(9-39) (approximately 4 ml normal saline) and then diluted in 100 ml 0.9% normal saline for every 10 mg exendin(9-39) (approximately 20 ml 0.9% normal saline), to which approximately 10 ml 25% human serum albumin was added (50 ml 25% human serum albumin for every 10 mg exendin(9-39)), for a total IV bolus infusion volume of approximately 34 ml. The IV bolus infusion was administered over 1 minute. The subcutaneous injection consisted of 0.025 mg/kg of lyophilized exendin(9-39) (which equates to a dose of approximately 2 mg for an 80 kg patient) solubilized in 0.2 ml normal saline and further diluted in 0.5 ml normal saline to a total volume of 0.7 ml for subcutaneous injection in the arm. Plasma exendin(9-39) concentrations were measured by liquid chromatography—mass spectrometry (LCMS) as described in Lasaosa et al., supra Example 1. As shown in FIG. 5B, the Cmax that was observed in subcutaneous administration of exendin(9-39) was significantly lower than the Cmax observed in intravenous administration of exendin(9-39), further supporting the hypothesis that for subcutaneous administration, a higher dose of exendin(9-39) would be required for preventing hyperinsulinemic hypoglycemia, as compared to efficacious doses of intravenously administered exendin(9-39).

A single ascending dose (SAD) study was performed to assess the pharmacokinetics, efficacy, and local tolerability of administering exendin(9-39) by subcutaneous injection. For the SAD study, nine subjects with hyperinsulinemic hypoglycemia were randomized to one of four experiments, each representing one of four subcutaneous doses of exendin(9-39): 7,500 pmol/kg, 37,500 pmol/kg, 75,000 pmol/kg, or 112,500 pmol/kg. Lyophilized exendin(9-39) acetate 10 mg/vial from Bachem (Clinalfa, Laufelfingen, Switzerland) was acquired for each experiment, with each 10 mg vial solubilized in 200 μl normal saline, then further diluted with normal saline to a total dose of 7,500 pmol/kg, 37,500 pmol/kg, 75,000 pmol/kg, or 112,500 pmol/kg (2.0 mg, 10 mg, 20 mg, or 30 mg of exendin(9-39), respectively, based on a patient weight of 80 kg). The total volume of each injectate was held constant, with further dilution of injectate as required to result in a total volume of injectate of 0.7 ml. Of the nine subjects, five subjects were randomized to receive one subcutaneous injection of 7,500 pmol/kg, 37,500 pmol/kg, 75,000 pmol/kg, or 112,500 pmol/kg (2, 10, 20, and 30 mg, respectively, based on an 80 kg patient) in a volume of 0.7 ml normal saline, and four subjects received two or more 0.7 ml injections of 75,000 pmol/kg, or 112,500 pmol/kg in order to maintain an injectate concentration of about 15 mg/ml or less.

Subjects fasted overnight for 12 hours and were admitted to the research clinic. One IV line was placed in the patient for blood collection. Fasting blood was drawn. Subjects were injected subcutaneously in the abdomen with the dose of exendin(9-39) to which they were randomized, and were blinded as to which dose they were receiving. For the subjects receiving a dose of 37,500 pmol/kg, 75,000 pmol/kg, or 112,500 pmol/kg, an OGTT was initiated at T+0 minutes, wherein patients were instructed to consume a 75 g glucola drink over 20 minutes. Plasma samples were collected at T-10, T-0, T+15, T+30, T+45, T+60, T+75, T+90, T+105, T+120, T+135, T+150, T+165, T+180, T+210, T+240, T+300, T+480, and T+1440, and at each timepoint the samples were immediately taken to the laboratory for processing.

The following parameters were evaluated: 1) plasma glucose, insulin, glucagon, GLP-1, and GIP concentration; 2) bioavailability/PK profile of subcutaneous exendin(9-39): Cmax, Tmax, AUC0_(−∞), AUClast, VZ, CL, T_(1/2), and bioavailability; 3) local tolerability after subcutaneous injection of exendin(9-39) utilizing a Visual Analog Scale (VAS) and a Numeric Rating Scale (NRS); and 4) local swelling as measured by caliper at timed intervals along the long and short axes of the swelling and bump height. Patients were also assessed for hypoglycemic symptoms using a graded symptom questionnaire in which patients rated the severity of specifically recited hypoglycemia symptoms from 1-5 (1: least severe; 5: most severe) at specific timepoints, from which a “Glucose Rise” score, “Glucose Fall” score, and “All Timepoints” score were calculated. Exendin(9-39) concentration was measured by liquid chromatograph-mass spectrometry as described by Lasaosa et al., supra Example 1.

For the 8 subjects who were administered a subcutaneous dose of 37,500 pmol/kg, 75,000 pmol/kg, or 112,500 pmol/kg, the plasma glucose concentrations were measured during the OGTT. (The dose of 7,500 pmol/kg that was administered to subject 1 was presumed to be subtherapeutic, and so an OGTT was not administered to this subject.) For the remaining eight subjects who were administered a subcutaneous dose of exendin(9-39) and an OGTT, none of the subjects became hypoglycemic after subcutaneous injection at doses ranging from 35,000-112,500 pmol/kg. Thus, prevention of hypoglycemia was achieved at all subcutaneous dose levels. In contrast, all of the subjects receiving placebo became hypoglycemic during the OGTT. As shown in FIG. 6, the average plasma nadir for the 8 subjects administered a subcutaneous dose of exendin(9-39) was 78 mg/dL, versus <50 mg/dL for the placebo. Additionally, as shown in Table 3, the average subject symptomatic response was significantly improved for the subjects who were administered the subcutaneous dose of exendin(9-39) and OGTT, as measured by a dramatically reduced Overall Symptom Score (14.6 vs. 20.6 for placebo) and Symptom Fall Score (4 vs. 22 for placebo).

As shown in Table 4, subcutaneous administration of exendin(9-39) as a single injection at a dose ranging from 37,500 pmol/kg to 112,500 pmol/kg (approximately 10-30 mg) and a constant volume of 0.7 ml was efficacious for preventing hypoglycemia, for example as shown by the plasma glucose nadir. An injectate concentration of approximately 15 mg/ml (the 37,500 pmol/kg dose) resulted in the greatest pharmacodynamic response, as defined by Cmax and dose-normalized Cmax. For the subjects who were subcutaneously administered exendin(9-39) at relatively equivalent concentrations (approximately 13-16 mg/ml), as shown in Table 5, exendin(9-39) administration was efficacious in preventing hypoglycemia, for example as shown by the plasma glucose nadir. For these patients, Table 5 shows that there was an increasingly favorable PK response with increasing dose, as defined by Cmax and T_(1/2).

As shown in FIG. 8, a strong correlation was found between the percent increase in plasma glucose nadir concentrations (comparing plasma glucose nadir after subcutaneous injection of exendin(9-39) to baseline plasma glucose nadir) and the peak plasma exendin(9-39) concentrations (Cmax).

Surprisingly, the clinical efficacy achieved for the subcutaneously administered doses of exendin(9-39) tested in this SAD study was equivalent to the efficacy that was achieved by continuous IV infusion of larger quantities of exendin(9-39) as described in Example 1, as shown for example in Table 3 for the plasma glucose nadir, AUC glucose, and the Symptom Fall Score parameters.

In view of the efficacy of the subcutaneously administered dose levels as demonstrated in this example, the efficacy, safety, tolerability, and pharmacokinetics of subcutaneous administration of exendin(9-39) over a defined time period is evaluated, for example, as described in Example 4 and Example 5 below.

4.4 Example 4: Multi-Ascending Dose Trial to Assess the Efficacy, Tolerability, and Pharmacokinetic Profile of BID Exendin(9-39) in Patients with Post-Bariatric Hyperinsulinemic Hypoglycemia

This example describes a Phase 2a clinical study protocol for evaluating the safety, tolerability, efficacy, and pharmacokinetic profile of BID exendin(9-39) administered subcutaneously over 3 days to patients with post-bariatric hyperinsulinemic hypoglycemia.

TABLE B Study objectives and endpoints: Objective Endpoint Primary: To evaluate the treatment Response rate in plasma glucose effect on plasma glucose of nadir, defined as proportion of SC BID Ex9 patients in each dose arm with no plasma glucose ≤50 mg/dL at any timepoint from 0-180 minutes during OGTT on Day 3 of treatment vs. on Day 0. Secondary: To evaluate the treatment Improvement in composite symptom effect on symptoms of score as compared to baseline hypoglycemia of SC BID Ex9 during OGTT on Day 3 of treatment vs. on Day 0. To assess the pharmacokinetics Plasma PK parameters include of SC BID Ex9 at each dose AUC_(0-12 h), C_(max), T_(max), T_(1/2), and C_(trough), level after SC injection. To assess the safety and AEs, laboratory parameters, vital tolerability of SC BID Ex9 signs; NMR score, VAS score. at each dose level

Overview:

The study is a single-blinded, dose-randomized, cross-over design study that is being conducted at the Stanford University School of Medicine. All subject visits will take place in the Clinical and Translational Research Unit (CTRU). Sixteen to twenty eligible subjects will be assigned to one of five dose levels (2.5 mg, 5 mg, 10 mg, 15 mg, 20 mg) to receive subcutaneous injection of BID exendin(9-39) administered for three days. After a baseline Oral Glucose Tolerance Test (OGTT) is conducted on Day 0 wherein metabolic and symptomatic analyses will occur, subjects will return to the research clinic on Day 1 to initiate a BID dosing schedule for 3 days. During this time, subjects will return daily for fasting labs in the morning, a morning dose, PK sampling, and an evening trough sample, followed immediately by the second daily dose at T+720 min. Safety, tolerability, and pharmacokinetic parameters will be measured on a daily basis for the full three day duration of the study, after which a repeat OGTT is performed on the morning of Day 3 after the morning dose to evaluate for efficacy (no hypoglycemia and reduction in composite symptom score). Day 4 will consist solely of clinical safety monitoring with a plasma trough drawn 1440 minutes after the last Day 3 injection. This study if properly conducted is expected to demonstrate that BID dosing can result in meaningful therapeutic activity in each dosing arm. See, FIG. 9.

Randomization/Blinding:

For the first four subjects dosed, the subjects were randomly assigned to one of the following dose levels: 2.5 mg, 5 mg, or 10 mg. The remaining subjects will be randomly assigned to one of the following dose levels: 10 mg, 15 mg, or 20 mg. All subjects will remain blinded throughout. With the exception of the PI and sub-investigator who will remain un-blinded for safety purposes, all site personnel including nurses and study coordinators, who conduct patient symptom surveys, will remain masked to treatment assignment.

Study Drug Preparation and Dispensation:

All doses will be prepared to a total concentration of ≤15 mg/ml of exendin(9-39) in normal saline. Each 10 mg vial of lyophilized exendin(9-39) will be diluted in either 1 ml normal saline if a 10 mg/ml concentration is administered, or 0.7 ml normal saline if a 14 mg/ml concentration is administered. For doses requiring total volume of injection >1 ml, 2 injections will be employed.

Oral Glucose Tolerance Test (OGTT):

The OGTT will consist of administration of one 75 mg gram glucola drink with 1 gram of crushed acetaminophen to be consumed over 20 minutes.

Assays:

Metabolic: glucose, c-peptide, insulin, GLP-1, GIP, glucagon; PK: AUC₀₋₇₂₀, C_(max), T_(max), T_(1/2), C_(trough).

Anticipated PK Profile:

It was anticipated, based on the prior results for a single subcutaneous injection (as shown in Example 3), that after administration of a 5 mg, 10 mg, 15 mg, or 20 mg dose the plasma concentration of exendin(9-39) would return to <20 ng/mL or even close to 0 ng/mL within 720 minutes of injection. However, based on the intermediate results of BID dosing for 3 days as shown in FIG. 10 and as discussed below, it is expected that administration of a 10-30 mg dose will result in a higher nadir, such as a nadir of about 30-80 ng/ml within 720 minutes after injection.

It is expected that a dosage of 5 mg BID, 10 mg, 15 mg or 20 mg BID exendin(9-39) will demonstrate a therapeutic benefit for one or more patients in the 3-day trial. A “therapeutic benefit” may be defined with reference to effect on plasma glucose. For example, in some instances a dosage of exendin(9-39) provides a therapeutic benefit for a patient when the patient has no plasma glucose ≤50 mg/dL at any timepoint from 0-180 minutes during OGTT on Day 3 of treatment as compared to Day 0. In some instances a dosage of exendin(9-39) provides a therapeutic benefit for a patient when the patient has at least a 15% increase in plasma glucose nadir during OGTT on Day 3 relative to Day 0. In some instances a dosage of exendin(9-39) provides a therapeutic benefit for a patient when the patient has at least a 15% increase in AUC glucose. In some instances a dosage of exendin(9-39) provides a therapeutic benefit for a patient when the patient has a statistically significant decrease in the severity of one or more symptoms of hypoglycemia overall during the OGTT and/or of neuroglycopenic symptoms elicited during the glucose “Fall” period of the OGTT relative to Day 0. In some instances a dosage of exendin(9-39) provides a therapeutic benefit for a patient having a plasma glucose nadir ≤50 mg/dL at baseline when the patient exhibits a plasma glucose nadir ≥55 mg/dL after a defined treatment period (e.g., after a 3 day treatment period).

Intermediate Results

Four subjects were randomized to one of three dose levels (2.5 mg, 5 mg, or 10 mg) to receive subcutaneous injection of BID exendin(9-39) administered for three days.

Patient 1 was administered a dose of 5 mg at a concentration of 10 mg in 1 ml, subcutaneously administered in the abdomen. For Patient 1, a 13.1% increase in AUC glucose was observed as compared to baseline, but hypoglycemia was not prevented, as defined by plasma glucose ≤50 mg/dL. Patient 2 was administered a dose of 2.5 mg at a concentration of 10 mg in 1 ml, subcutaneously administered in the abdomen. For Patient 2, an 8.8% increase in AUC glucose was observed, but hypoglycemia was not prevented, as defined by plasma glucose ≤50 mg/dL. Patient 3 was administered a dose of 5 mg at a concentration of 10 mg in 1 ml, subcutaneously administered in the arm. For Patient 3, a 16.3% increase in AUC glucose was observed, but hypoglycemia was not prevented, as defined by plasma glucose ≤50 mg/dL.

Patient 4 was administered a dose of 10 mg at a concentration of 10 mg in 1 ml, subcutaneously administered in the arm. For this patient, hypoglycemia was not prevented, as defined by plasma glucose ≤50 mg/dL.

These intermediate pharmacodynamic results demonstrate an increasing therapeutic benefit, as defined by % increase in glucose AUC with increasing doses administered, with one of the two patients dosed with 5 mg experiencing a greater than 15% increase in AUC glucose as compared to AUC glucose during a baseline oral glucose tolerance test. While hypoglycemia as defined by plasma glucose ≤50 mg/dL was not prevented, a therapeutic dose response was achieved, illustrating that doses of 10-30 mg will result in improved glycemic control, as further shown by Example 3 and FIG. 8.

The pharmacokinetic parameters obtained from the 3-day BID dosing of Patents 1-4 are shown in Table 6 below. The single subject dosed at 10 mg for 3 days was severely disabled, experiencing daily episodes of symptomatic neuroglycopenia, and requiring placement of gastrostomy tube into the remnant stomach for route of nutrient administration. These intermediate results demonstrate that total exendin(9-39) exposure increases with increasing dose. As shown in Table 6, AUC was increased by about 1.5-1.7-fold, and Cmax was increased by about 50% with a 5 mg dose escalation from 5 mg to 10 mg. Similar degrees of increase are expected to be observed for AUC and Cmax with an escalation to a 15 mg dose. For a 15 mg dose, a Cmax value is expected to be in the therapeutically effective range of approximately 150-200 ng/ml. Interim pharmacokinetic results from this 3-day trial also demonstrate that on average, AUC plasma concentrations increase with increasing days of BID dosing. A higher trough was observed at Day 3 than at Day 1, suggesting several days (e.g., 3-5 days) may be required to reach steady state. Thus, the results of this study support efficacy of the 15 mg dose at Day 3 of treatment. The results of this study also support efficacy of the 10 mg dose in less severely disabled patients and/or with longer (e.g., 5 days) treatment.

Comparison of the pharmacokinetic responses to abdominal versus arm injection of 5 mg doses in patient 1 and patient 3 demonstrates that a quicker absorption profile with higher exposure as defined by Cmax (see Table 6) can be achieved by administration of the injectate into an area with less subcutaneous fat, as may be the abdominal subcutaneous area after bariatric surgery weight loss. A slower absorption profile with longer exposure, as defined by AUClast (see Table 6) can be achieved by administration of the same dose into an area with relatively more subcutaneous fat, such as the arm area may have after bariatric surgery weight loss.

4.5 Example 5: Multiple Doses of Subcutaneously Injected Exendin(9-39) Safely and Effectively Reverse Hyperinsulinemic Hypoglycemia

This example demonstrates the method of the invention in which a multi-site multi-ascending dose (MAD) format is used to evaluate the efficacy, safety, and pharmacokinetics of a 28-day trial of immediate release subcutaneous exendin(9-39) administered BID in patients with severe post-bariatric hypoglycemia. The primary objective of this trial is to demonstrate the efficacy of exendin(9-39) on plasma glucose levels during a 3-hour oral Glucose Tolerance Test (OGTT) at the end of 4-week treatment. This trial is also intended to demonstrate the efficacy of exendin(9-39) on the frequency and severity of hypoglycemia incidence and associated symptoms in patients with severe post-bariatric hypoglycemia. This trial also demonstrates the pharmacokinetics and pharmacodynamics of exendin(9-39) at each dose level. Furthermore, this trial demonstrates the safety and tolerability profile of the immediate release subcutaneous formulation of exendin(9-39) in patients with severe post-bariatric hypoglycemia.

This is a multi-center, double-blind, randomized, placebo-controlled, parallel-group, two exendin(9-39) dose levels, phase 2 study in patients with severe post-bariatric hypoglycemia. Approximately 36 patients will be recruited. Eligible patients will have a confirmed diagnosis of severe hypoglycemia post-bariatric via Whipple's triad and OGTT. The study is divided into three phases, as follows:

Screening Phase:

All potential subjects will complete an oral glucose tolerance test (OGTT), wherein if plasma glucose falls to less than or equal to 60 mg/dL and all other eligibility criteria are met, the patient will be allowed to enroll in the study. In cases of out of range laboratory values, with the exception of laboratory tests related to re-feeding syndrome, subjects are permitted to re-screen one time.

4-Week Randomized Treatment (RT) Period:

All enrolled subjects will participate in a 4-week randomized treatment period wherein subjects will be randomized to one of two exendin(9-39) doses (e.g., 10 mg and 20 mg, 10 mg and 15 mg, or 15 mg and 20 mg) administered BID or matching placebo of the 2 doses. The ratio of treatment assignment to the first exendin(9-39) BID dose, the second exendin(9-39) BID dose, the first matching placebo dose, and the second matching placebo dose will be 2:2:1:1. During the RT period, the subjects will undergo continuous glucose monitoring wearing Dexcoms at home.

Open-Label Extension (OLE) Period:

All patients completing Week 4 of the randomized treatment period and experiencing benefit with exendin(9-39) at the end of RT will be eligible to enter the OLE period. During the OLE period, the dose administered will either be an optimal fixed dose level selected at the end of the randomized treatment period of the study or up-titrated to 20 mg BID until any of the following occur: completed 12 months of the open-label extension; unacceptable toxicity; lack of efficacy; protocol deviation; patient withdrew consent; lost to follow-up; death; and study discontinues per the sponsor.

The primary efficacy endpoint is measured as the response rate in plasma glucose level at the end of the 4-week RT, defined as the proportion of patients either (1) without plasma glucose ≤55 mg/dL for patients whose glucose nadir is ≤50 mg/dL at baseline OGTT; or (2) without plasma glucose ≤60 mg/dL for patients whose glucose nadir is 55-≤60 mg/dL at baseline OGTT. Secondary efficacy endpoints are measured as the improvement in neuroglycopenic symptom score during OGTT at the end of RT (Week 4), where neuroglycopenic symptoms include inability to concentrate, confusion, weakness, drowsiness, dizziness, blurred vision, difficulty speaking (modified from the Edinburgh Hypoglycemia Score, Hepburn 1991); the proportion of patients with severe hypoglycemia during the 4-week RT, where severe hypoglycemia is defined an event requiring assistance of another person to actively administer carbohydrates, glucagon, or take other corrective actions with a blood glucose concentration of <50 mg/dL by continuous glucose monitoring (CGM); the proportion of patients with any hypoglycemia event between Week 2 and Week 4, where hypoglycemia is defined as a plasma glucose concentration of ≤55 mg/dL by continuous glucose monitoring (CGM) [Hypoglycemia after Roux-En-Y gastric bypass: detection rates of continuous glucose monitoring (CGM) versus mixed meal test Kefurt 2014]; and the Change in Quality of life at Week 4 from baseline as evaluated using Short-Form 36 (SF-36) domain scores.

The pharmacokinetic and pharmacodynamics endpoints to be measured include C_(max), T_(max), T_(1/2), C_(trough), AUC of exendin(9-39). Exploratory endpoints will include insulin (AUC, Peak, ISR, ICR), GLP-1/GIP, and glucagon concentrations.

It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety for all purposes.

TABLE 1 Subject metabolic responses to OGTT with and without intravenous infusion of Extendin (9-39) vs. non-surgical controls HH Placebo^(a) HH Ex(9-39)^(a) Non-Surg controls^(a) (n = 8) (n = 8) P-value^(b) P-value^(c) P-value^(d) Fasting plasma glucose (mg*dl⁻¹) 91.8 ± 1.2 94.7 ± 3.9 100.6 ± 4.3  0.414 0.06  0.322 Peak postprandial glucose (mg*dl⁻¹) 235.4 ± 11.0 225.5 ± 15.1 152.3 ± 6.1  0.432 0.000 0.001 Time to peak glucose (min) 56.3 ± 3.8 37.5 ± 4.9 45.0 ± 5.7 0.011 0.120 0.334 Nadir postprandial glucose (mg*dl⁻¹) 46.1 ± 1.9 78.7 ± 5.4 74.9 ± 3.8 0.000 0.000 0.570 Time to hypoglycemia (min) 137.5 ± 5.3  NA NA NA NA NA Delta peak-nadir glucose (mg*dl⁻¹) 189.3 ± 10.1 146.8 ± 15.3 77.4 ± 7.6 0.012 0.000 0.001 Rate of glucose decline (mg*dl⁻¹*min⁻¹)  3.1 ± 0.5  1.1 ± 0.3  0.5 ± 0.2 0.001 0.001 0.189 AUC glucose (0, 60)(mg*dl⁻¹*min⁻¹) 10402.5 ± 309.3  10905.9 ± 624.1  8120.6 ± 287.1 0.278 0.000 0.001 AUC glucose(60, 180)(mg*dl⁻¹*min⁻¹) 11318.9 ± 573.3  15397.5 ± 1180.7 13346.3 ± 504.9  0.010 0.019 0.378 AUC glucose(0, 180)(mg*dr⁻¹*min⁻¹) 21721.4 ± 701.8  26303.4 ± 1785.8 21466.9 ± 642.2  0.020 0.793 0.023 Fasting plasma insulin (uU*ml⁻¹)  4.0 ± 19.2  3.2 ± 0.8 15.0 ± 1.2 0.260 0.000 0.000 Peak postprandial insulin (uU*ml⁻¹) 200.3 ± 28.5  88.3 ± 23.0 86.0 ± 8.3 0.000 0.002 0.928 Time to peak insulin (min) 60.0 ± 5.7 48.8 ± 5.5  67.5 ± 12.4 0.285 0.590 0.187 AUC insulin (0, 60)(uU*ml⁻¹*min⁻¹) 6220.3 ± 766.4 3368.9 + 832.4 3420.0 ± 375.7 0.001 0.005 0.956 AUC insulin (60, 180)(uU*ml−1*min−1) 4591.6 ± 876.3 2462.2 ± 524.8 6532.5 ± 607.9 0.038 0.090 0.000 AUC insulin (0, 180)(uU*ml⁻¹*min⁻¹) 13605.5 + 1819.0  5831.1 ± 1281.0 9952.5 ± 869.9 0.001 0.092 0.019 Insulin at glucose <55 mg/dl (uU*ml⁻¹) 17.5 ± 4.7 NA NA NA NA NA Insulinogenic Index (0, 30)  1.2 ± 0.2  0.7 ± 0.2  1.2 ± 0.4 0.001 0.927 0.286 Insulinogenic Index (0, 60)  1.4 ± 0.2  0.6 ± 0.1  1.9 ± 0.4 0.000 0.239 0.006 ^(a)Data are presented as mean ± SEM ^(b-d)P⁻value by two-sided student's t-test ^(b)P⁻value HH Placebo vs. HH Ex(9-39) ^(c)P⁻value HH Placebo vs. Non-Surg Controls ^(d)P⁻value HH Ex(9-39) vs. Non-Surg Controls

TABLE 2 Subject incretin responses to OGTT with and without intravenous infusion of Exendin (9-39) HH Placebo^(a) HH Ex(9-39)^(a) (n = 8) P-value^(b) Fasting GLP-1 (pmol*L⁻¹)  9.0 ± 0.4  9.4 ± 1.2 0.191 Peak GLP-1 (pmol*L⁻¹) 86.0 ± 6.1  82.3 ± 13.9 0.857 Time to peak GLP-1 (min) 42.9 ± 6.1 38.6 ± 5.5 0.604 AUC GLP-1 (0, 60)(pmol*L⁻¹*min⁻¹) 3270.0 ± 214.1 3267.9 ± 606.8 0.998 AUC GLP-1 (60, 180)(pmol*L⁻¹*min⁻¹) 3135.7 ± 265.7 3621.4 ± 416.0 0.429 AUC GLP-1 (0, 180)(pmol*L⁻¹*min⁻¹) 6405.7 ± 423.0 6889.3 ± 941.2 0.700 Peak Insulin to Peak GLP-1 ratio  2.6 ± 0.1  1.3 ± 0.4 0.059 Fasting GIP (pmol*L−1*min−1) 14.4 ± 1.4 14.0 ± 1.5 0.824 Peak GIP (pmol*L−1*min−1)  93.1 ± 12.8  86.6 ± 12.0 0.005 Time to peak GIP (min) 42.9 ± 6.0 34.3 ± 4.3 0.356 AUC GIP (0, 60)(pmol*L⁻¹*min⁻¹) 3831.4 ± 495.9 3267.9 ± 606.8 0.127 AUC GIP (60, 180)(pmol*L⁻¹*min⁻¹) 3722.1 ± 168.9 3165.0 ± 396.9 0.084 AUC GIP (0, 180)(pmol*L⁻¹*min⁻¹) 7553.6 ± 617.9 6420.0 ± 941.2 0.003 Peak Insulin to Peak GIP ratio  2.4 ± 0.4  1.3 ± 0.4 0.000 Fasting glucagon (pmol*L⁻¹) 40.5 ± 2.8 41.9 ± 2.9 0.567 Peak glucagon (pmol*L⁻¹) 82.8 ± 6.7 92.3 ± 6.4 0.079 Time to peak glucagon (min)  60.0 ± 12.7  45.0 ± 11.3 0.470 AUC glucagon (0, 60)(pmol*L⁻¹*min⁻¹) 3796.6 ± 306.2 4430.5 ± 285.1 0.033 AUC glucagon (60, 180)(pmol*L⁻¹*min⁻¹) 7999.8 ± 912.2 8017.5 ± 696.3 0.981 AUC glucagon (0, 180)(pmol*L⁻¹*min⁻¹) 11584.4 ± 1252.9 12019.3 ± 941.9  0.981

TABLE 3 Placebo^(a) SC Ex(9-39)^(a) IV Ex(9-39)^(a) (n = 8) (n = 8) (n = 8) P-value^(b) P-value^(c) Subject metabolic response Fasting plasma glucose (mg*dl⁻¹) 91.6 ± 1.7 94.5 ± 1.7 94.7 ± 3.9 0.125 0.956 Peak postprandial glucose (mg*dl⁻¹) 229.3 ± 13.2 252.3 ± 23.7 225.5 ± 15.1 0.258 0.358 Time to peak glucose (min) 54.5 ± 3.7 52.5 ± 4.9 37.5 ± 4.9 0.351 0.049 Nadir postprandial glucose (mg*dl⁻¹) 47.7 ± 1.6 77.9 ± 4.1 78.7 ± 5.4 <.001 0.906 Time to hypoglycemia (min) 135.5 ± 4.9  NA NA NA NA Delta peak-nadir glucose (mg*dl⁻¹) 182.0 ± 11.0 174.4 ± 24.2 146.8 ± 15.3 0.588 0.351 Rate of glucose decline (mg*dl⁻¹*min⁻¹)  2.9 ± 0.4  2.4 ± 0.7  1.1 ± 0.3 0.402 0.117 AUC glucose (0, 60)(mg*dl⁻¹*min⁻¹) 10171.4 ± 334.6  11135.6 ± 704.4  10905.9 ± 624.1  0.140 0.811 AUC glucose(0, 180)(mg*dl⁻¹*min⁻¹)  21106 ± 1001.6 27471.6 ± 1963.0 26303.4 ± 1785.8 0.007 0.667 Subject symptomatic response Overall Symptom Score{circumflex over ( )}  26 ± 3.3 14.6 ± 4.4  4.5 ± 2.2 0.006 0.057 Symptom Rise Score+  11 ± 2.4 12.3 ± 3.7  4.3 ± 2.2 0.794 0.087 Symptom Fall Score*  22 ± 3.5  4.0 ± 1.5  1.1 ± 0.4 0.001 0.091 ^(a)Data are presented as mean ± SEM ^(b-c)P⁻value by two-sided paired student's t-test ^(b)P⁻value SC Ex(9-39) vs. Placebo ^(c)P⁻value SC Ex(9-39) vs. IV Ex(9-39)

TABLE 4 37500 75000 125000 pmol/kg pmol/kg pmol/kg n = 1 n = 2 n = 1 Injectate Characteristics Fold-increase in dose relative to 5x 10x 15x 7,500 pmol/kg Concentration (mg/ml) 15.714 23.57 41.43 Total dose administered (mg) 11

 17 29 Volume per injection (ml) 0.7 0.7 0.7 Number of injections 1 1 1 Subject Pharmacodynamic Response Fasting plasma glucose (mg*dl⁻¹) 94 95.8 103.5 Peak postprandial glucose (mg*dl⁻¹) 244 226.8 311.0 Time to peak glucose (min) 60 60 60 Nadir postprandial glucose (mg*dl⁻¹) 88 71.3 58.0 Delta peak-nadir glucose (mg*dl⁻¹) 156 155.5 253.0 Rate of glucose decline (mg*dl⁻¹*min⁻¹) 1 2.2 6.7 AUC glucose (0, 60)(mg*dl⁻¹*min⁻¹) 10815 9694 12713 AUC glucose(0, 180)(mg*dl⁻¹*min⁻¹) 28482 25151 25718 Subject Pharmacokinetic Response Cmax (ng/ml) 114

 73.35 56 DN Cmax (ng/mL/mg) 10.36 4.45 1.93 Tmax (h) 3.25 6.25 5.00 AUCINF [h*ng/ml] 1097

 1210 728 DN_AUC_(INF) [h*ng/ml/mg] 69

 63 24 AUC_(last) (h*ng/ml] 1084

 696 720 T^(1/2)(h) 3.60

 9.14 3.64 MRT_(last) [h]) 6.16

 5.74 6.62 MRT_(INF) [h] 6.45

 14.66 6.87

TABLE 5 37500 75000 112500 pmol/kg pmol/kg pmol/kg n = 1 n = 1 n = 2 Injectate Characteristics Fold-increase in dose relative to 7,500 pmol/kg Concentration (mg/ml) 15.714 14.71 13.48 Total dose administered (mg) 11 21

 29 Volume per injection (ml) 0.7 0.7 0.7 Number of injections 1 2 3 Subject Pharmacodynamic Response Fasting plasma glucose (mg*dl⁻¹) 94 90

 90.0 Peak postprandial glucose (mg*dl⁻¹) 244 187.0

 228.0 Time to peak glucose (min) 60 30

 45 Nadir postprandial glucose (mg*dl⁻¹) 88 75.5

 85.0 Delta peak-nadir glucose (mg*dl⁻¹) 156 111.5

 143.0 Rate of glucose decline (mg*dl⁻¹*min⁻¹) 1 0.6

 1.5 AUC glucose (0, 60)(mg*dl⁻¹*min⁻¹) 10815 9540

 11063 AUC glucose(0, 180)(mg*dl⁻¹*min⁻¹) 28482 21023

 27274 Subject Pharmacokinetic Response Cmax (ng/ml) 114 158 229 DN Cmax (ng/mL/mg) 10.36 7.52 7.9 Tmax (h) 3.25 4.50 4.50 AUCINF [h*ng/ml] 1097 1516 1885 DN_AUC_(INF) [h*ng/ml/mg] 69 101 67 AUC_(last) (h*ng/ml] 1084 900 1055 T^(1/2)(h) 3.60 4.59 4.87 MRT_(last) [h]) 6.16 4.39 4.69 MRT_(INF) [h] 6.45 8.55 9.24

TABLE 6 Dose 2.5 mg 5 mg 5 mg 10 mg Number of subjects dosed n = 3 n = 1 n = 1 n = 1 Injectate Characteristics Dose (mg) 2.5 5 5 10 Concentration (mg/ml) 10 mg/ml 10 mg/ml 10 mg/ml 10 mg/ml Volume per injection (ml) 0.25 ml 0.5 ml 0.5 ml 1 ml Number of injections 1 1 1 1 Location of administration abdomen abdomen arm arm Subject Pharmacodynamic Response % Increase AUC glucose (treatment-baseline) 8.8 13.1 16.3 N/A Plasma glucose nadir ≤50 mg/dL (Yes/No) Yes Yes Yes Yes Subject Pharmacokinetic Response Day 3 Cmax (ng/ml) 53.4 77.2 65 128 DN Cmax (ng/mL/mg) 21.36 15.44 13 12.8 Tmax Day 3 (h) 4 5 5 5 AUClast (h*ng/ml] 379.2 409.1 684.3 989 T1/2(h) 4.3 4.4 4.6 6.5 

The invention claimed is:
 1. A method for treating hyperinsulinemic hypoglycemia in a subject, the method comprising subcutaneously administering to the subject in need thereof an isotonic solution comprising a therapeutically effective amount of exendin(9-39) and at least one of an antimicrobial preservative, a tonicity adjusting agent, or a buffer; wherein the therapeutically effective amount is 10-30 mg of exendin(9-39); and wherein the exendin(9-39) is administered at a concentration of 4-20 mg/ml.
 2. The method of claim 1, wherein the tonicity adjusting agent comprises mannitol.
 3. The method of claim 1, wherein the therapeutically effective amount is 10-20 mg of exendin(9-39).
 4. The method of claim 1, wherein the exendin(9-39) is administered once per day.
 5. The method of claim 1, wherein the exendin(9-39) is administered twice per day.
 6. The method of claim 1, wherein the patient has previously had bariatric surgery.
 7. The method of claim 6, wherein the bariatric surgery is Roux-en-Y gastric bypass, vertical sleeve gastrectomy, placement of an endosleeve device, duodenal mucosal resurfacing, partial bypass of the duodenum, vagal nerve blockade, or pyloroplasty.
 8. The method of claim 1, wherein the patient has previously had gastrointestinal surgery.
 9. The method of claim 8, wherein the gastrointestinal surgery is gastrectomy, Nissen Fundoplication, or esophagectomy.
 10. A method for treating hyperinsulinemic hypoglycemia in a subject, the method comprising subcutaneously administering to the subject in need thereof a therapeutically effective amount of exendin(9-39), wherein the therapeutically effective amount is 10-30 mg of exendin(9-39); wherein the exendin(9-39) is administered at a concentration of 4-20 mg/ml; and wherein the exendin(9-39) is encapsulated in an extended release capsule.
 11. The method of claim 10, wherein the extended release capsule comprises a microsphere.
 12. The method of claim 11, wherein the microsphere comprises a biopolymer.
 13. The method of claim 10, wherein the extended release capsule is a nano-lipocapsule.
 14. The method of claim 10, wherein the therapeutically effective amount is 10-20 mg of exendin(9-39).
 15. The method of claim 10, wherein the exendin(9-39) is administered once per day.
 16. The method of claim 10, wherein the exendin(9-39) is administered twice per day.
 17. The method of claim 10, wherein the patient has previously had bariatric surgery.
 18. The method of claim 17, wherein the bariatric surgery is Roux-en-Y gastric bypass, vertical sleeve gastrectomy, placement of an endosleeve device, duodenal mucosal resurfacing, partial bypass of the duodenum, vagal nerve blockade, or pyloroplasty.
 19. The method of claim 10, wherein the patient has previously had gastrointestinal surgery.
 20. The method of claim 19, wherein the gastrointestinal surgery is gastrectomy, Nissen Fundoplication, or esophagectomy.
 21. A method for treating hyperinsulinemic hypoglycemia in a subject, the method comprising: solubilizing lyophilized exendin(9-39) with saline or other pharmacologically acceptable diluent to form an exendin(9-39) solution; and subcutaneously administering to the subject in need thereof a therapeutically effective amount of the exendin(9-39) solution; wherein the therapeutically effective amount is 10-30 mg of exendin(9-39); and wherein the exendin(9-39) is administered at a concentration of 4-20 mg/ml.
 22. The method of claim 21, wherein the lyophilized exendin(9-39) is provided in dual-chamber cartridge.
 23. The method of claim 21, wherein the exendin(9-39) solution is administered using a pen injector.
 24. A method for treating hyperinsulinemic hypoglycemia in a subject, the method comprising: subcutaneously administering to the subject in need thereof a therapeutically effective amount of exendin(9-39) for a first treatment period, wherein the exendin(9-39) is administered at a first dosage; and subcutaneously administering to the subject a therapeutically effective amount of exendin(9-39) for a second treatment period after the first treatment period, wherein the exendin(9-39) is administered at a second dosage.
 25. The method of claim 24, wherein the second dosage is greater than the first dosage.
 26. The method of claim 24, wherein the first dosage is a morning dosage.
 27. The method of claim 24, wherein the second dosage is an evening dosage.
 28. The method of claim 24, wherein the first dosage is from 10-15 mg of exendin(9-39).
 29. The method of claim 24, wherein the second dosage is from 10-20 mg of exendin(9-39). 